W. R. Berkley (WRB) 10-K risk factor changes: FY2025 vs FY2024

[added: In addition to those] described below, our businesses may also be adversely affected by risks and uncertainties not currently known to us or that we currently consider immaterial.

The demand for insurance is influenced primarily by general economic conditions, [added: including the impact of tariffs,] while the supply of insurance is often directly related to available capacity based on the perceived profitability of the business.

At times, we [removed: have faced] [added: face] significant competition in our business as a result of existing insurers seeking to gain or maintain market share as well as new entrants and capital providers.

These competitors within the reinsurance market include Swiss Re, Munich Re, Berkshire Hathaway and [removed: Partner] [added: Hannover] Re.

[removed: We expect that perceived] [added: Perceived] financial strength, in particular, [removed: will become more] [added: is] important as customers seek high quality reinsurers.

This intense competition could cause the supply and/or demand for insurance or reinsurance to change, which affect our ability to price our products at attractive rates and retain existing business or write new products at adequate rates or on terms [removed: and conditions acceptable to us.]

[removed: Recently, insurance prices have generally increased] [added: Rates] for [removed: most lines of business, excluding] workers' compensation and certain professional liability lines of [removed: business.][added: business continue to decrease.]

[added: Current price levels for certain lines of business] may remain below the prices required for us to achieve our long-term return objectives.

Our gross reserves for losses and loss expenses were approximately [removed: $20.4] [added: $22.2] billion as of December 31, [removed: 2024.][added: 2025.]

For example, current accident year catastrophe losses net of reinsurance recoveries were [removed: $298] [added: $336] million in [removed: 2024, $195] [added: 2025, $298] million in [removed: 2023,] [added: 2024] and [removed: $212] [added: $195] million in [removed: 2022.][added: 2023.]

Changing climate conditions may alter the frequency and increase the severity of catastrophic events and thereby adversely affect our financial condition and [removed: results.][added: results of operations.]

Any increase in the frequency or severity of natural disasters may adversely affect our financial condition and [removed: results.][added: results of operations.]

We, as a primary insurer, may have significant exposure [removed: for] [added: to] terrorist acts.

Based on our [removed: 2024] [added: 2025] earned premiums, our aggregate deductible under TRIPRA during [removed: 2025] [added: 2026] is approximately [removed: $1,663] [added: $1,835] million.

To the extent that our reinsurers have excluded coverage for certain terrorist acts or have priced this coverage at rates that make purchasing such coverage economically infeasible, we may not have reinsurance protection and could be exposed to [removed: potential] [added: potentially significant] losses as a result of any acts of terrorism.

In addition, the [removed: new] [added: current] U.S. administration and the volatile political environment increases the chance of other federal legislative and regulatory changes that could affect us in ways we cannot predict.

As described in “International Regulation” above, the EU has [removed: recently amended] [added: adopted amendments to] certain provisions in Solvency II, which EU member states [removed: will implement] [added: are] in [added: the process of implementing in] their domestic regulation over [removed: the next two years.][added: 2025 and 2026.]

Additionally, our capital requirements and compliance requirements may be adversely affected if the European Commission does not deem the insurance [removed: regulatory regimes of the jurisdictions outside the EU in which we have insurance or reinsurance companies domiciled to be “equivalent” to Solvency II.]

However, the two regimes, and their respective requirements, [removed: have begun] [added: continue] to diverge due to both the EU’s [removed: recent] amendments to Solvency II described above and the reforms to the U.K.’s domestic prudential regime (please see “International Regulation” above for more information).

We may be unable to maintain all required licenses and approvals and our business may not fully comply with the [added: wide variety of applicable laws and regulations or the relevant authority's interpretation of the laws and regulations.]

We face additional risks as a result of our international operations which could have an adverse effect on our results of operations and financial condition including: burdens and costs of compliance with a variety of foreign laws and regulations and the associated risk and costs of non-compliance; exposure to undeveloped or evolving legal systems, which may result in unpredictable or inconsistent application of laws and regulations; exposure to commercial, political, legal or regulatory corruption; political, economic or other instability in countries in which we conduct business, including possible terrorist acts; the imposition of [added: existing or future] tariffs, trade barriers or other protectionist laws or business practices that favor local competition, increased costs and adverse effects on our business; changes to visa or immigration policies; diminished ability to enforce our contractual rights; potential increased risk of data breaches; differences in cultural environments; sociopolitical instability; social, political or economic instability resulting from climate change; changes in regulatory requirements, including changes in regulatory treatment of certain products or services; exposure to local economic conditions and its impact on our clients’ performance and creditworthiness; and restrictions on the repatriation of non-U.S. investments and earnings.

As of December 31, [removed: 2024,] [added: 2025,] the amount due from our reinsurers was approximately $3,558 million, including amounts due from state funds and industry pools where it was intended that we would bear no risk.

Our financial results could be adversely affected by acquired businesses not performing as projected, unforeseen liabilities, routine and unanticipated transaction-related charges, diversion of management time and resources to acquisition integration challenges or growth strategies, loss of key employees, challenges in integrating information technology systems of acquired companies with our own, amortization of expenses related to intangibles, charges [added: for impairment of long-term assets or goodwill and indemnification.]

A shutdown of, or inability to access, one or more of our facilities, a power outage or a failure of one or more of our information technology, [removed: telecommunications or] [added: telecommunications,] other computer [removed: systems] [added: systems, or other critical infrastructure] could significantly impair our employees' ability to perform such functions on a timely basis.

In the event of a disaster such as a natural catastrophe, terrorist attack or industrial accident, physical or electronic security breaches, such as breaches by computer hackers, the infection of our systems [added: by a malicious computer virus, denial of service attack, or other cybersecurity incident, our systems could be inaccessible for an extended period of time.]

If our business continuity plans or system security does not sufficiently address such a business interruption, system failure or service denial, our ability to write and process new and renewal business, provide customer service, pay claims in a timely manner or perform other necessary business functions could be significantly impaired and our business [added: and results of operations] could be harmed.

Although we have taken [added: reasonable] steps intended to protect our data and information technology [removed: systems] [added: systems,] and [added: to] mitigate [removed: the] [added: potential] risk of harm caused by cybersecurity incidents or breaches, no safeguards are perfect and any failure of these safeguards could cause a substantial disruption of our business operations, which could result in service interruptions, data security compromises, regulatory action, and other similar operational and legal issues, as well as substantial remediation and other costs.

Cybersecurity breaches, including physical or electronic break-ins, computer viruses, malware, attacks by hackers, ransomware attacks, phishing attacks, supply chain attacks, breaches due to employee error or misconduct and other similar breaches can create system disruptions, shutdowns or unauthorized access to, or disclosure of, information maintained in our information technology systems and in the information technology systems of our vendors and other third [removed: parties.][added: parties on which we rely.]

We expect cybersecurity threats to continue to occur in the future and we are constantly [removed: managing efforts] [added: responding] to [added: these threats to] infiltrate and compromise our systems and data.

Our failure to effectively protect sensitive personal and/or proprietary information, whether owing to breaches of our own systems or those of our vendors and other third parties, could result in significant monetary and reputational damages, material adverse effects to our financial [removed: condition, costly litigation, or other regulatory enforcement actions.]

[removed: Use] [added: Our increasing investment in and use] of artificial intelligence technologies [removed: by us] or [added: their use by] third-parties on which we rely could expose us to technological, security, legal, and other risks.

Products or services offered that develop or [removed: adopt] [added: employ] artificial intelligence (“AI”) technologies, including generative AI and machine learning, offer potential benefits (e.g., [removed: with respect to] efficiency) but likewise may raise technological, security, legal and other risks and challenges that may adversely affect our operations, business, or reputation.

[added: In addition,] AI technologies may be misused, and that risk is increased by the relative newness of the technology, the speed at which it is being adopted, and ongoing uncertainty with respect to the laws, regulations, and standards governing its [added: development and deployment federally, across states, and internationally.]

Moreover, because some AI technologies [removed: are relatively new,] such as generative [removed: AI,] [added: AI are relatively new and rapidly evolving,] many of the potential risks regarding their use are currently unknown.

As of December 31, [removed: 2024,] [added: 2025,] our investment in fixed maturity securities was approximately [removed: $22.4] [added: $25.0] billion, or [removed: 75.0%] [added: 75.3%] of our total investment portfolio including cash and cash equivalents.

As of that date, our portfolio of fixed maturity securities consisted of the following types of securities: U.S. Government securities [removed: (10.0%);] [added: (16.0%);] state and municipal securities [removed: (10.5%);] [added: (7.4%);] corporate securities [removed: (37.6%);] [added: (34.7%);] asset-backed securities [removed: (17.3%);] [added: (15.2%);] mortgage-backed securities [removed: (16.8%)] [added: (19.2%)] and foreign government [removed: (7.8%).][added: (7.5%).]

There may be certain asset classes that were in active markets with significant observable data that become illiquid [added: due to the then current financial environment.]

Although the historical rates of default on state and municipal securities have been relatively low, our state and municipal fixed maturity securities could be subject to a higher risk of default or impairment due to declining municipal tax bases and [removed: revenue.][added: revenue, particularly in the event of a recession.]

At December 31, [removed: 2024,] [added: 2025,] our investment in these assets was approximately [removed: $5.5] [added: $5.6] billion, or [removed: 18.4%,] [added: 17.1%,] of our investment portfolio, including cash and cash equivalents.

Merger and arbitrage trading securities were [removed: $1.1] [added: $1.2] billion, or [removed: 3.8%] [added: 3.7%] of our investment portfolio, including cash and cash equivalents at December 31, [removed: 2024.][added: 2025.]

Recently, insurance rates have generally moderated for many lines of business, particularly for property lines, which in some instances are experiencing rate decreases.

and conditions acceptable to us.

Recently, insurance rate increases have generally moderated for many lines of business, particularly for property lines, which in some instances are experiencing rate decreases.

Rates for workers' compensation and certain professional liability lines of business continue to decrease.

Loss costs continue to increase, principally due to continued social inflation.

regulatory regimes of the jurisdictions outside the EU in which we have insurance or reinsurance companies domiciled to be “equivalent” to Solvency II.

Adverse economic factors, including recessions, inflation, periods of high unemployment, the impact of tariffs or lower economic activity could result in the sale of fewer policies than expected or an increase in frequency or severity of claims and premium defaults or both, which, in turn, could affect our growth and profitability.

Numerous factors, such as business revenue, economic conditions, the impact of tariffs, the volatility and strength of the capital markets and inflation can affect the business and economic environment.

These same factors affect our ability to generate revenue and profits.

In an economic downturn that is characterized by higher unemployment, declining spending and reduced corporate revenues, the demand for insurance products is generally adversely affected, which directly affects our premium levels and profitability.

Negative economic factors may also affect our ability to receive the appropriate rate for the risk we insure with our policyholders and may adversely affect the number of policies we can write, including with respect to our opportunities to underwrite profitable business.

In an economic downturn, customers may have less need for insurance coverage, cancel existing insurance policies, modify their coverage or not renew the policies they hold.

Existing policyholders may exaggerate or even falsify claims to obtain higher claims payments.

These outcomes would reduce our underwriting profit to the extent these factors are not reflected in the rates we charge.

Given the inherent uncertainty of models, the usefulness of such models as a tool to evaluate risk is subject to a high degree of uncertainty that could result in actual losses that are materially different than our estimates.

A deviation from our loss estimates may adversely impact, perhaps significantly, our financial results.

Our approach to risk management relies on subjective variables that entail significant uncertainties.

For example, we consider estimates of probability of exceedance and deterministic scenarios for certain events that are generated by computer-run models.

In addition, we use historical data and scenarios, among other factors, to analyze and manage credit and interest rate risks in our investment portfolio.

It is possible that actual events could give rise to losses materially different to those estimated by these models.

Small changes in assumptions, which depend heavily on our judgment and foresight, can have a significant impact on the modeled outputs.

For example, catastrophe models that simulate loss estimates based on a set of assumptions are important tools used to estimate our exceedance probability curves.

These assumptions address a number of factors that impact loss potential including, but not limited to, the characteristics of a given natural catastrophe event; the increase in claim costs resulting from limited supply of labor and materials needed for repairs following a catastrophe event (demand surge); the types, function, location and characteristics of exposed risks; susceptibility of exposed risks to damage from an event with specific characteristics; and the financial and contractual provisions of the (re)insurance contracts that cover losses arising from an event.

We run many model simulations in order to understand the impact of these assumptions on a catastrophe’s loss potential.

Furthermore, there are risks associated with catastrophe events, which are either poorly represented or not represented at all by catastrophe models.

Each modeling assumption or un-modeled risk introduces uncertainty into estimated modeled losses that management must consider.

These uncertainties can include, but are not limited to, the following:

- The models do not address all the possible hazard characteristics of a catastrophe peril (e.g. the precise path and wind speed of a hurricane);

- The models may not accurately reflect the true frequency of events;

- The models may not accurately reflect a risk's vulnerability or susceptibility to damage for a given event characteristic;

- The models may not accurately represent loss potential to insurance or reinsurance contract coverage limits, terms and conditions; and

- The models may not accurately reflect the impact on the economy of the area affected or the financial, judicial, political, or regulatory impact on insurance claim payments during or following a catastrophe event.

As a result of these factors and contingencies, our reliance on assumptions and data used to estimate exceedance probability curves and modeled scenario losses is subject to a high degree of uncertainty that could result in actual losses that are materially different from our modeled estimates and our financial results could be adversely affected.

Our employees could take excessive risks, which could negatively affect our financial condition and business.

As an insurance enterprise, we are in the business of binding certain risks.

The employees who conduct our business, including executive officers and other members of management, underwriters, product managers and other employees, do so in part by making decisions and choices that involve exposing us to risk.

These include decisions such as setting underwriting guidelines and standards, product design and pricing, determining which business opportunities to pursue and other decisions.

We endeavor, in the design and implementation of our compensation programs and practices, to avoid giving our employees incentives to take excessive risks.

Employees may, however, take such risks regardless of the structure of our compensation programs and practices.

Similarly, although we employ controls and procedures designed to monitor employees’ business decisions and prevent them from taking excessive risks, these controls and procedures may not be effective.

In addition to those

Over the past several years, premium rates have increased for most lines of business, while they have decreased in others, most notably workers' compensation and certain professional liability lines of business.

However, loss costs have also increased and the duration and magnitude of the improved pricing environment remains uncertain.

Despite higher interest rates, current price levels for certain lines of business

The COVID-19 pandemic, including the related impact on the U.S. and global economies, materially and adversely affected our results of operations.

wide variety of applicable laws and regulations or the relevant authority's interpretation of the laws and regulations.

for impairment of long-term assets or goodwill and indemnification.

by a malicious computer virus, denial of service attack, or other cybersecurity incident, our systems could be inaccessible for an extended period of time.

development and deployment federally, across states, and internationally.

due to the then current financial environment.

the voting securities of that insurer or any parent company of such insurer.

- the need for advance notice in order to raise business or make nominations at stockholders' meetings.

While providing our [removed: business units] [added: businesses] with certain operating autonomy, our structure allows us to capitalize on the benefits of economies of scale through centralized capital, investment, reinsurance, enterprise risk management, and actuarial, financial and corporate compliance support.

The following presents a discussion of accounting policies and estimates relating to reserves for losses and loss expenses, assumed reinsurance [removed: premiums] [added: premiums, allowance for expected credit losses] and [removed: other-than-temporary impairments of] [added: fair value measurements on] investments.

[removed: Examples of changes in terms and conditions that can have a significant impact on reserve levels are the use of] aggregate policy limits, the expansion of coverage exclusions, whether or not defense costs are within policy limits, and changes in deductibles and attachment points.

The following table reflects the impact of changes (which could be favorable or unfavorable) in frequency and severity, relative to our assumptions, on our loss estimate for claims occurring in [removed: 2024:][added: 2025:]

Our net reserves for losses and loss expenses of approximately [removed: $17.2] [added: $19.0] billion as of December 31, [removed: 2024] [added: 2025] relate to multiple accident years.

Approximately [removed: $3.3] [added: $3.4] billion, or [removed: 19.1%,] [added: 18.0%,] of the Company’s net loss reserves as of December 31, [removed: 2024] [added: 2025] relate to the Reinsurance & Monoline Excess segment.

[removed: In the case of assumed reinsurance our] loss reserve estimates are based, in part, upon information received from ceding companies.

[added: Furthermore, due to] delayed reporting of claim information by ceding companies, the claim settlement tail for assumed reinsurance is also extended.

Following is a summary of the Company’s reserves for losses and loss expenses by business segment as of December 31, [removed: 2024] [added: 2025] and [removed: 2023:][added: 2024:]

| (In thousands) | | | [added: 2025 | | | | | |] 2024 | | | | | | 2023 | | | [added: | | | | | |]

| Insurance | | | $ | [removed: 13,881,574] [added: 15,534,168] | | | | | $ | [removed: 12,430,202] [added: 13,881,574] | |

| Reinsurance & Monoline Excess | | | [removed: 3,285,067] [added: 3,419,506] | | | | | | [removed: 3,231,618] [added: 3,285,067] | | |

| Net reserves for losses and loss expenses | | | [removed: 17,166,641] [added: 18,953,674] | | | | | | [removed: 15,661,820] [added: 17,166,641] | | |

| Ceded reserves for losses and loss expenses | | | [removed: 3,201,389] [added: 3,254,099] | | | | | | [removed: 3,077,832] [added: 3,201,389] | | |

| Gross reserves for losses and loss expenses | | | $ | [removed: 20,368,030] [added: 22,207,773] | | | | | $ | [removed: 18,739,652] [added: 20,368,030] | |

Following is a summary of the Company’s net reserves for losses and loss expenses by major line of business as of December 31, [removed: 2024] [added: 2025] and [removed: 2023:][added: 2024:]

(1)Reserves for excess and assumed workers’ compensation business are net of an aggregate net discount of [removed: $405] [added: $420] million and [removed: $390] [added: $405] million as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] respectively.

Net prior year development [removed: (i.e,] [added: (i.e.,] the sum of prior year reserve changes and prior year earned premiums changes) for each of the last three years ended December 31, are as follows:

| (In thousands) | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | | | | | | | |

| Increase in prior year loss reserves | | | $ | [removed: (14,350)] [added: (34,446)] | | | | | $ | [removed: (29,681)] [added: (14,350)] | | | | | $ | [removed: (54,511)] [added: (29,681)] | | | | | | | |

| Increase in prior year earned premiums | | | [removed: 18,782] [added: 37,692] | | | | | | [removed: 10,782] [added: 18,782] | | | | | | [removed: 18,106] [added: 10,782] | | | | | | | | |

| Net favorable (unfavorable) prior year development | | | $ | [removed: 4,432] [added: 3,246] | | | | | $ | [removed: (18,899)] [added: 4,432] | | | | | $ | [removed: (36,405)] [added: (18,899)] | | | | | | | |

The Company believes that [removed: commercial] auto-related claims are being particularly impacted by social inflation, which is contributing to an increase in the frequency of large losses beyond expectations.

The favorable excess workers’ compensation development was driven by continued lower claim frequency and reported losses relative to expectations, and [removed: to] favorable claim settlements spread across many prior accident years.

Insurance [removed: – Reserves] [added: –Reserves] for the Insurance segment developed unfavorably by $21 million in 2023 (net of additional and return premiums).

In particular, losses related to U.S. winter storms which occurred during the month of December 2022 were a significant contributor to the development, as information gathering and evaluation [removed: of many of these claims were still ongoing into the new year.]

[removed: The Company believes] [added: impacted by] social [removed: inflation] [added: inflation, which] is contributing to an increase in the frequency of large losses [removed: for these accident years.][added: beyond expectations.]

It should also be noted that commercial auto liability experienced adverse prior year development for the 2020 through 2022 accident years, which partially offset the favorable development discussed above; the adverse development was driven [removed: by a larger than expected number of large losses reported.]

The favorable [removed: excess] workers’ compensation development was driven by continued lower claim frequency and reported losses relative to [removed: our] expectations, and [removed: favorable claim settlements.][added: was spread across many prior accident years, mainly 2017 through 2024.]

The unfavorable development for non-proportional reinsurance assumed liability and excess general liability was associated primarily with our U.S. assumed reinsurance business, and related to accounts [removed: reinsuring excess and umbrella business and construction projects.]

[removed: Unfavorable] [added: Favorable] prior year development (net of additional and return premiums) was [removed: $36] [added: $3] million in [removed: 2022.][added: 2025.]

Insurance – Reserves for the Insurance segment developed unfavorably by [removed: $41] [added: $44] million in [removed: 2022] [added: 2025] (net of additional and return premiums).

[removed: The development was driven] by a larger than expected number of large losses reported.

Reinsurance & Monoline Excess – Reserves for the Reinsurance & Monoline Excess segment developed favorably by [removed: $5] [added: $47] million in [removed: 2022] [added: 2025] (net of additional and return premiums).

The unfavorable [removed: professional liability and non-proportional reinsurance assumed liability] development [added: for casualty reinsurance] was concentrated mainly in accident years [removed: 2016] [added: 2019] through [removed: 2018] [added: 2023] and was associated primarily with [removed: our U.S.] [added: non-proportional] assumed [removed: reinsurance business and related to accounts insuring construction projects and professional liability exposures.][added: reinsurance.]

The [removed: unfavorable development for commercial] [added: adverse] auto liability [added: development] was concentrated in [removed: the 2021] accident [removed: year and related to commercial auto program business.][added: years 2021 through 2023.]

The amount of workers’ compensation reserves that were discounted was [removed: $1,358] [added: $1,400] million and [removed: $1,352] [added: $1,358] million at December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] respectively.

The aggregate net discount for those reserves, after reflecting the effects of ceded reinsurance, was [removed: $405] [added: $420] million and [removed: $390] [added: $405] million at December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] respectively.

At December 31, [removed: 2024,] [added: 2025,] discount rates by year ranged from 0.7% to 6.5%, with a weighted average discount rate of 3.6%.

Substantially all discounted workers’ compensation reserves (97% of total discounted reserves at December 31, [removed: 2024)] [added: 2025)] are excess workers’ compensation reserves.

Examples of changes in terms and conditions that can have a significant impact on reserve levels are the use of

| 1% | | | $ | 154,823 | | | | | $ | 466,010 | | | | | $ | 854,993 | |

| 5% | | | 466,010 | | | | | | 789,520 | | | | | | 1,193,909 | | |

| 10% | | | 854,993 | | | | | | 1,193,909 | | | | | | 1,617,554 | | |

In the case of assumed reinsurance our

| December 31, 2025 | | | | | | | | | | | | | | | | | |

| Other liability | | | $ | 2,385,364 | | | | | $ | 5,903,742 | | | | | $ | 8,289,106 | |

| Professional liability | | | 673,774 | | | | | | 1,582,133 | | | | | | 2,255,907 | | |

| Workers’ compensation (1) | | | 1,103,703 | | | | | | 760,075 | | | | | | 1,863,778 | | |

| Auto | | | 828,000 | | | | | | 1,032,528 | | | | | | 1,860,528 | | |

| Short-tail lines (2) | | | 438,813 | | | | | | 826,036 | | | | | | 1,264,849 | | |

| Total Insurance | | | 5,429,654 | | | | | | 10,104,514 | | | | | | 15,534,168 | | |

| Reinsurance & Monoline Excess (1) (3) | | | 1,670,518 | | | | | | 1,748,988 | | | | | | 3,419,506 | | |

| Total | | | $ | 7,100,172 | | | | | $ | 11,853,502 | | | | | $ | 18,953,674 | |

The adverse development was driven by the other liability and auto liability lines of business, and was partially offset by favorable development for short tail lines of business, auto physical damage, professional liability and workers’ compensation.

The adverse other liability development was driven mainly by umbrella and excess liability claims, and to a lesser degree from the Company’s primary surplus lines casualty business.

The umbrella and excess liability development included a significant component stemming from underlying auto exposures.

The other liability development was concentrated in accident years 2017 through 2022.

An increase in the frequency of litigated claims is also driving up both indemnity and loss adjustment expense in these lines of business beyond expectations.

The favorable development for both short tail lines of business and auto physical damage related to the 2024 accident year, and resulted from favorable settlements of both catastrophe and non-catastrophe property claims below our expectations.

The favorable professional liability development related mainly to accident years 2022 and 2023, and was driven by lower reported claim frequency and incurred losses than expected.

The favorable workers’ compensation development was mainly related to accident years 2023 and 2024, and resulted from a continuation of favorable reported claim frequency below expectations, although the magnitude of the favorable development in this line has moderated from levels seen in previous years.

The favorable development was driven mainly by property and workers’ compensation business, and was partially offset by adverse development in casualty reinsurance assumed.

Similar to the Insurance segment, the favorable property development related primarily to the 2024 accident year and resulted from favorable claims settlements below our expectations.

The Company believes that commercial auto-related claims are being particularly

of many of these claims were still ongoing into the new year.

The favorable excess workers’ compensation development was driven by continued lower

claim frequency and reported losses relative to our expectations, and favorable claim settlements.

reinsuring excess and umbrella business and construction projects.

| Foreign government | | | 67 | | | | | | $ | 151,002 | | | | | $ | 165,721 | |

| Corporate | | | 24 | | | | | | 43,968 | | | | | | 814 | | |

| Total | | | 110 | | | | | | $ | 226,172 | | | | | $ | 167,695 | |

| Independent pricing services | | | $ | 24,614,659 | | | | | 98.4 | | % |

| Observable data | | | 232,066 | | | | | | 0.9 | | |

| Total | | | $ | 25,017,056 | | | | | 100.0 | | % |

| (In thousands) | | | 2025 | | | | | | 2024 | | |

| (In thousands) | | | 2025 | | | | | | 2024 | | | | | | 2025 | | | | | | 2024 | | |

The average annualized yield for fixed maturity securities excluding Argentine inflation-linked securities was 4.7% in 2025

and 4.5% in 2024.

The gains

Commencing with the first quarter of 2024, the Company reclassified a program management business from the Insurance segment to the Reinsurance & Monoline Excess segment.

The reclassified business is a program management business offering support on a nationwide basis for commercial casualty and property program administrators.

Reclassifications have been made to the Company's 2023 and 2022 financial information to conform with this presentation.

On June 12, 2024, the Company announced that its Board of Directors approved a 3-for-2 common stock split which was paid in the form of a stock dividend to holders of record as of June 24, 2024.

The additional shares were issued on July 10, 2024.

Shares outstanding and per share amounts in this Form 10-K reflect such 3-for-2 common stock split.

| 1% | | | $ | 142,388 | | | | | $ | 428,582 | | | | | $ | 786,324 | |

| 5% | | | 428,582 | | | | | | 726,110 | | | | | | 1,098,020 | | |

| 10% | | | 786,324 | | | | | | 1,098,020 | | | | | | 1,487,640 | | |

Furthermore, due to

| December 31, 2023 | | | | | | | | | | | | | | | | | |

| Other liability | | | $ | 1,912,594 | | | | | $ | 4,607,507 | | | | | $ | 6,520,101 | |

| Professional liability | | | 527,555 | | | | | | 1,438,102 | | | | | | 1,965,657 | | |

| Workers’ compensation (1) | | | 1,019,445 | | | | | | 790,944 | | | | | | 1,810,389 | | |

| Auto | | | 645,707 | | | | | | 700,850 | | | | | | 1,346,557 | | |

| Short-tail lines (2) | | | 375,129 | | | | | | 412,369 | | | | | | 787,498 | | |

| Total Insurance | | | 4,480,430 | | | | | | 7,949,772 | | | | | | 12,430,202 | | |

| Reinsurance & Monoline Excess (1) (3) | | | 1,673,581 | | | | | | 1,558,037 | | | | | | 3,231,618 | | |

| Total | | | $ | 6,154,011 | | | | | $ | 9,507,809 | | | | | $ | 15,661,820 | |

The ultimate net impact of COVID-19 on the Company's reserves remains uncertain.

As of December 31, 2024, the Company had recognized losses for COVID-19-related claims activity, net of reinsurance, of approximately $381 million, of which $326 million relates to the Insurance segment and $55 million relates to the Reinsurance & Monoline Excess segment.

Such $381 million of COVID-19-related losses included $379 million of reported losses and $2 million of IBNR.

The unfavorable development in the segment primarily related to COVID-19 losses at two businesses.

These businesses wrote policies providing coverage for event cancellation and film production delay which were heavily impacted by losses directly caused by the COVID-19 pandemic.

Most of this COVID-19 related unfavorable development emerged during the third quarter as a result of settlements of claims at values higher than our expectations.

However, the Company believes that

as a result of these settlements the remaining level of uncertainty around the ultimate value of its known COVID-19 claims has been significantly reduced.

The unfavorable development mentioned above also includes favorable prior year development for the Insurance segment primarily attributable to the 2020 and 2021 accident years and unfavorable development on the 2015 through 2019 accident years.

The favorable development on the 2020 and 2021 accident years was concentrated in certain casualty lines of business including general liability, professional liability, and workers’ compensation.

The Company experienced lower reported claim frequency in these lines of business during 2020 and 2021 relative to historical averages, and continued to experience lower reported incurred losses relative to its expectations for these accident years as they developed during 2022.

These trends began in 2020 and we believe were caused by the impacts of the COVID-19 pandemic, including for example, lockdowns, reduced driving/traffic and increased work from home.

Due to the uncertainty regarding the ultimate impacts of the pandemic on accident years 2020 and 2021 incurred losses, the Company was cautious in reacting to these lower trends in

setting and updating its loss ratio estimates for these years.

As these accident years have continued to mature, the Company has continued to recognize some of the favorable reported experience in its ultimate loss estimates made during 2022.

The unfavorable development on the 2015 through 2019 accident years was concentrated in the general liability and professional liability, including medical professional, lines of business, as well as auto liability.

The overall favorable development for the segment was driven mainly by favorable development in excess workers compensation, substantially offset by unfavorable development in the professional liability, non-proportional reinsurance assumed liability, and commercial auto liability lines of business.

The favorable excess workers’ compensation development was spread across most prior accident years, including 2012 and prior years, and was driven by a review of the Company’s claim reporting patterns as well as a number of favorable claim settlements relative to expectations.

other factors.

| Foreign government | | | 50 | | | | | | $ | 138,388 | | | | | $ | 157,424 | |

| Corporate | | | 19 | | | | | | 50,525 | | | | | | 2,922 | | |

The effective duration for the fixed maturity portfolio (including cash and cash equivalents) was [removed: 2.6] [added: 3.0] years and [removed: 2.4] [added: 2.6] years at December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] respectively.

The following table outlines the groups of fixed maturity securities and their effective duration at December 31, [removed: 2024:][added: 2025:]

| Mortgage-backed securities | | | 4.3 | | | | | | [removed: $] [added: 4,810,392] | [removed: 3,767,851] | |

| U.S. government and government agencies | | | [removed: 3.7] [added: 4.7] | | | | | | [removed: 2,235,341] [added: $] | [added: 3,998,038] | |

| State and municipal | | | 2.7 | | | | | | [removed: 2,338,256] [added: 1,866,758] | | |

| Loans receivable | | | 2.4 | | | | | | [removed: 405,248] [added: 419,074] | | |

| Cash and cash equivalents | | | 0.0 | | | | | | [removed: 1,404,931] [added: 1,957,438] | | |

The estimated fair value at specified levels at December 31, [removed: 2024] [added: 2025] would be as follows:

| Corporate | | | 3.0 | | | | | | 8,687,411 | | |

| Foreign government | | | 2.9 | | | | | | 1,875,589 | | |

| Asset-backed securities | | | 1.3 | | | | | | 3,810,346 | | |

| Total | | | 3.0 | | | | | | $ | 27,425,046 | |

| 300 basis point rise | | | $ | 24,844,553 | | | | | $ | (2,580,493) | |

| 200 basis point rise | | | 25,687,653 | | | | | | (1,737,393) | | |

| 100 basis point rise | | | 26,564,356 | | | | | | (860,690) | | |

| Base scenario | | | 27,425,046 | | | | | | — | | |

| 100 basis point decline | | | 28,182,512 | | | | | | 757,466 | | |

| 200 basis point decline | | | 28,826,079 | | | | | | 1,401,033 | | |

| 300 basis point decline | | | 29,451,916 | | | | | | 2,026,869 | | |

| | | | | | | | | | | | |

| Foreign government | | | 2.7 | | | | | | 1,755,325 | | |

| Corporate | | | 2.6 | | | | | | 8,417,641 | | |

| Asset-backed securities | | | 1.4 | | | | | | 3,885,012 | | |

| Total | | | 2.6 | | | | | | $ | 24,209,605 | |

| 300 basis point rise | | | $ | 22,258,604 | | | | | $ | (1,951,001) | |

| 200 basis point rise | | | 22,898,254 | | | | | | (1,311,351) | | |

| 100 basis point rise | | | 23,555,609 | | | | | | (653,996) | | |

| Base scenario | | | 24,209,605 | | | | | | — | | |

| 100 basis point decline | | | 24,827,143 | | | | | | 617,538 | | |

| 200 basis point decline | | | 25,393,892 | | | | | | 1,184,287 | | |

| 300 basis point decline | | | 25,928,699 | | | | | | 1,719,094 | | |

Of our [removed: 58] [added: 60] businesses, [removed: 51] [added: 53] have been organized and developed internally and seven have been added through acquisition.

| (In thousands) | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | | | | | | | | | | | | | | | | | | | |

| Insurance | | | $ | [removed: 10,549,550] [added: 11,183,713] | | | | | $ | [removed: 9,560,533] [added: 10,549,550] | | | | | $ | [removed: 8,609,028] [added: 9,560,533] | | | | | | | | | | | | | | | | | | | |

| Reinsurance & Monoline Excess | | | [removed: 1,422,546] [added: 1,527,614] | | | | | | [removed: 1,393,934] [added: 1,422,546] | | | | | | [removed: 1,395,042] [added: 1,393,934] | | | | | | | | | | | | | | | | | | | | |

| Total | | | $ | [removed: 11,972,096] [added: 12,711,327] | | | | | $ | [removed: 10,954,467] [added: 11,972,096] | | | | | $ | [removed: 10,004,070] [added: 10,954,467] | | | | | | | | | | | | | | | | | | | |

| Insurance | | | [removed: 88.1] [added: 88.0] | | % | | | | [removed: 87.3] [added: 88.1] | | % | | | | [removed: 86.1] [added: 87.3] | | % | | | | | | | | | | | | | | | | | | |

| Reinsurance & Monoline Excess | | | [removed: 11.9] [added: 12.0] | | | | | | [removed: 12.7] [added: 11.9] | | | | | | [removed: 13.9] [added: 12.7] | | | | | | | | | | | | | | | | | | | | |

Our twenty-three insurance company subsidiaries rated by Standard & Poor's (“S&P”) have financial strength ratings of [removed: A+] [added: AA-] (the [removed: fifth] [added: fourth] highest rating out of twenty-seven possible ratings).

In addition, [removed: through our non-U.S. insurance businesses,] we have [removed: the capability to write business in 87 countries worldwide,] [added: extensive worldwide capabilities,] with branches or offices in [removed: 40] [added: 52] cities outside the United States, in Asia, Australia, Canada, Continental Europe, Mexico, Scandinavia, South [removed: America] [added: America,] and the United [removed: Kingdom.][added: Kingdom, and through Lloyds’ global licensing.]

The distribution of products is limited [removed: solely] to wholesale brokers.

*Berkley Fire & Marine* offers [removed: a broad range of preferred] [added: specialized insurance products and services for] inland marine and related property [removed: risks and services to customers throughout the United States.][added: risks, nationwide.]

[removed: Products] [added: These products] are distributed through independent agents and brokers.

*Berkley Insurance Asia* underwrites specialty commercial insurance coverages to clients in [removed: North] Asia [removed: and Southeast Asia] through offices in Hong Kong, India, Shanghai and Singapore.

The management liability coverages [removed: they provide] [added: provided] include directors and officers, employment practices, fiduciary, cyber, crime and miscellaneous professional liability.

Berkley Transactional, a division of Berkley Professional Liability, underwrites [removed: a full suite of] transactional insurance products, including representations and warranties insurance, and tax opinion insurance.

[removed: *W / R / B Underwriting*] [added: *Berkley Specialty London*] provides a broad range of insurance products to the Lloyd's marketplace, with a concentration in specialist classes of business including property, professional indemnity and financial lines.

| | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | | | | | | | | | | | | | | | | | | | |

| Acadia Insurance | | | 5.4% | | | | | | 5.4% | | | | | | [removed: 5.3%] [added: 5.4%] | | | | | | | | | | | | | | | | | | | | |

| Admiral Insurance | | | [removed: 7.3] [added: 7.9] | | | | | | [removed: 7.0] [added: 7.3] | | | | | | [removed: 6.3] [added: 7.0] | | | | | | | | | | | | | | | | | | | | |

| Berkley Accident and Health | | | [removed: 5.9] [added: 6.8] | | | | | | [removed: 5.4] [added: 5.9] | | | | | | [removed: 5.2] [added: 5.4] | | | | | | | | | | | | | | | | | | | | |

| Berkley Agribusiness | | | [removed: 0.6] [added: 0.5] | | | | | | [removed: 0.8] [added: 0.6] | | | | | | 0.8 | | | | | | | | | | | | | | | | | | | | |

| Berkley Alliance Managers | | | [removed: 2.3] [added: 2.2] | | | | | | [removed: 2.4] [added: 2.3] | | | | | | [removed: 2.8] [added: 2.4] | | | | | | | | | | | | | | | | | | | | |

| Berkley Aspire | | | [removed: 1.3] [added: 1.4] | | | | | | [removed: 1.2] [added: 1.3] | | | | | | [removed: 1.0] [added: 1.2] | | | | | | | | | | | | | | | | | | | | |

| Berkley Asset Protection | | | 0.9 | | | | | | 0.9 | | | | | | [removed: 1.0] [added: 0.9] | | | | | | | | | | | | | | | | | | | | |

| Berkley Canada | | | 1.0 | | | | | | 1.0 | | | | | | [removed: 1.2] [added: 1.0] | | | | | | | | | | | | | | | | | | | | |

| Berkley Construction Solutions | | | [removed: 0.7] [added: 0.8] | | | | | | [removed: 0.6] [added: 0.7] | | | | | | [removed: 0.4] [added: 0.6] | | | | | | | | | | | | | | | | | | | | |

| Berkley Custom Insurance | | | [removed: 2.9] [added: 2.8] | | | | | | 2.9 | | | | | | [removed: 3.2] [added: 2.9] | | | | | | | | | | | | | | | | | | | | |

| Berkley Cyber Risk Solutions | | | [removed: 0.7] [added: 0.6] | | | | | | [removed: 0.8] [added: 0.7] | | | | | | [removed: 0.9] [added: 0.8] | | | | | | | | | | | | | | | | | | | | |

| Berkley Enterprise Risk Solutions | | | 0.2 | | | | | | [removed: 0.1] [added: 0.2] | | | | | | [removed: —] [added: 0.1] | | | | | | | | | | | | | | | | | | | | |

| Berkley Entertainment | | | [removed: 1.6] [added: 1.7] | | | | | | [removed: 1.7] [added: 1.6] | | | | | | [removed: 1.9] [added: 1.7] | | | | | | | | | | | | | | | | | | | | |

| Berkley Environmental | | | [removed: 7.3] [added: 7.6] | | | | | | [removed: 6.7] [added: 7.3] | | | | | | [removed: 5.7] [added: 6.7] | | | | | | | | | | | | | | | | | | | | |

| Berkley Fire & Marine | | | 0.8 | | | | | | [removed: 0.9] [added: 0.8] | | | | | | [removed: 0.8] [added: 0.9] | | | | | | | | | | | | | | | | | | | | |

| Berkley Healthcare | | | [removed: 1.2] [added: 1.1] | | | | | | [removed: 1.5] [added: 1.2] | | | | | | [removed: 1.8] [added: 1.5] | | | | | | | | | | | | | | | | | | | | |

| Berkley Human Services | | | [removed: 1.4] [added: 0.7] | | | | | | [removed: 1.3] [added: 1.4] | | | | | | [removed: 1.1] [added: 1.3] | | | | | | | | | | | | | | | | | | | | |

| Berkley Industrial Comp | | | [removed: 0.8] [added: 0.9] | | | | | | [removed: 0.7] [added: 0.8] | | | | | | 0.7 | | | | | | | | | | | | | | | | | | | | |

| Berkley Insurance Asia | | | [removed: 0.7] [added: 0.6] | | | | | | [removed: 0.8] [added: 0.7] | | | | | | 0.8 | | | | | | | | | | | | | | | | | | | | |

| Berkley Insurance Australia | | | [removed: 1.4] [added: 1.3] | | | | | | [removed: 1.6] [added: 1.4] | | | | | | [removed: 1.7] [added: 1.6] | | | | | | | | | | | | | | | | | | | | |

| Berkley Latinoamérica | | | [removed: 3.3] [added: 3.4] | | | | | | [removed: 3.2] [added: 3.3] | | | | | | [removed: 3.0] [added: 3.2] | | | | | | | | | | | | | | | | | | | | |

| Berkley Life Sciences | | | [removed: 0.5] [added: 0.6] | | | | | | 0.5 | | | | | | 0.5 | | | | | | | | | | | | | | | | | | | | |

| Berkley Luxury Group | | | [removed: 0.7] [added: 0.8] | | | | | | 0.7 | | | | | | [removed: 0.8] [added: 0.7] | | | | | | | | | | | | | | | | | | | | |

*Berkley Edge* provides excess and surplus lines coverage for small to mid-sized commercial accounts that generally consist of hard-to-place, specialized risks involving moderate to high degrees of hazard.

In both general liability and professional lines, Berkley Edge offers limited coverage options and distributes its products through a limited group of wholesale brokers.

*Berkley Embedded Solutions* delivers tailored, digital-first insurance products and services at the point of purchase.

| Berkley Specialty London | | | 3.9 | | | | | | 4.1 | | | | | | 3.9 | | | | | | | | | | | | | | | | | | | | |

| | | | 2025 | | | | | | 2024 | | | | | | 2023 | | | | | | | | | | | | | | | | | | | | |

Our program business offers insurance support for program administrators.

| | | | 2025 | | | | | | 2024 | | | | | | 2023 | | | | | | | | | | | | | | | | | | | | |

| | | | 2025 | | | | | | 2024 | | | | | | 2023 | | | | | | | | | | | | | | | | | | | | |

| | | | 2025 | | | | | | 2024 | | | | | | 2023 | | | | | | | | | | | | | | | | | | | | |

| | | | 2025 | | | | | | 2024 | | | | | | 2023 | | | | | | | | | | | | | | | | | | | | |

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| | | | 2025 | | | | | | 2024 | | | | | | 2023 | | | | | | | | | | | | | | | | | | | | |

| (In thousands) | | | 2025 | | | | | | 2024 | | | | | | 2023 | | | | | | | | |

| Ceded reserves | | | 3,254,099 | | |

These statutes also provide that all transactions among members of a holding company system must be fair and reasonable and, if material or of specified types, such transactions require prior notice and approval or non-disapproval by the domiciliary insurance regulator.

In December 2024, the IAIS adopted a risk-based, group-wide global insurance capital standard (“ICS”) applicable to IAIGs.

In the U.S., a group calculation tool developed by the NAIC uses a risk-based capital aggregation methodology applied to all members of such group.

The methodology uses a group capital ratio defined as the aggregate available capital divided by aggregate required capital.

In 2024, the IAIS concluded that this aggregation methodology provides a comparable basis for the implementation of the ICS in the United States.

The IAIS will undertake detailed assessments of member jurisdictions' methodologies for implementation of the ICS as early as 2027.

The NAIC is currently working on refinements to the methodology in connection with the IAIS's assessment.

In 2020,

The CPRA also established a new agency, the California Privacy Protection Agency, authorized to enforce the CCPA and promulgate regulations — including regulations that came into effect on January 1, 2026, to clarify the application of the CCPA to insurance companies.

Proposed updates reflect the extensive innovations in technology since the model regulation's initial adoption in 2020.

The AI Bulletin has been adopted and issued by approximately half of U.S. states.

The Colorado Division of Insurance has indicated its intent to extend these regulations to other lines of insurance.

In December 2025, the NAIC proposed for comment a regulatory framework focused on insurers' use of data and predictive models provided by third parties.

In November 2025, the Ninth Circuit granted an injunction pending appeal staying the enforcement of California Senate Bill 261, the California law requiring certain companies to publish a climate risk report.

The Dodd-Frank Act also incorporated the Nonadmitted and Reinsurance Reform Act of 2010 (“NRRA”), which became effective on July 21, 2011, and establishes national uniform standards on how states may regulate and tax surplus lines insurance.

In particular, the NRRA gives regulators in the home state of an insured exclusive authority to regulate and tax surplus lines insurance transactions.

In August 2023, the NAIC adopted revisions to its Nonadmitted Insurance Model Act intended to implement the changes to the regulation of surplus lines insurance resulting from the NRRA.

The PRA’s amendments were implemented in full from the end of 2024.

We have received notice from

| W/R/B Underwriting | | | 4.1 | | | | | | 3.9 | | | | | | 3.7 | | | | | | | | | | | | | | | | | | | | |

| Ceded reserves | | | 3,201,389 | | |

Our excess and

IAIS member states, including the U.S., will now update their domestic insurance group capital requirements where necessary to fully reflect the ICS.

We received notice from the Delaware Department of Insurance in 2024 that we are considered an IAIG.

In the United States, the NAIC has developed a group capital calculation tool that uses a risk-based capital aggregation methodology to aggregate the available capital and the minimum capital of each entity in an insurance group regardless of their structure.

The NAIC has indicated that it intends to work domestically on its approach to the group capital aggregation method with respect to U.S. implementation of the ICS.

The amendments take effect in phases that began in 2023 and continue through 2025.

An increasing number of U.S. states have adopted,

The deadline to finalize the amendments was recently extended until December 31, 2025.

The AI Bulletin may be adopted and issued by state regulators to licensed insurers.

In 2024, the NAIC formed a new task force to develop and propose a regulatory framework for the oversight of insurers’ use of third-party data and predictive models, the drafting of which is expected to begin in 2025.

It is expected that Colorado will further adopt governance and testing regulations for other lines of insurance.

associated with climate change.

The PRA’s amendments took effect throughout 2024.

For the fiscal year ended December 31, [removed: 2024][added: 2025]

The aggregate market value of the registrant's common stock held by non-affiliates as of June 30, [removed: 2024,] [added: 2025,] the last business day of the registrant’s most recently completed second fiscal quarter, was [removed: $15,700,741,833.][added: $21,940,921,884.]

Number of shares of common stock, $.20 par value, outstanding as of February [removed: 13, 2025: 379,226,056][added: 23, 2026: 374,490,856]

Portions of the Company’s definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, [removed: 2024,] [added: 2025,] are incorporated herein by reference in Part III.

| [SAFE HARBOR [removed: STATEMENT](#i00f6c772b2784a239fcaf48012a18d4d_10)] [added: STATEMENT](#i7163b5f722664d73b2f16cd636a9c985_10)] | | | | | | | | | | | |

| ITEM | | | 1. | | | [removed: [BUSINESS](#i00f6c772b2784a239fcaf48012a18d4d_16)] [added: [BUSINESS](#i7163b5f722664d73b2f16cd636a9c985_16)] | | | [removed: [6](#i00f6c772b2784a239fcaf48012a18d4d_16)] [added: [7](#i7163b5f722664d73b2f16cd636a9c985_16)] | | |

| ITEM | | | 1A. | | | [RISK [removed: FACTORS](#i00f6c772b2784a239fcaf48012a18d4d_19)] [added: FACTORS](#i7163b5f722664d73b2f16cd636a9c985_19)] | | | [removed: [25](#i00f6c772b2784a239fcaf48012a18d4d_19)] [added: [29](#i7163b5f722664d73b2f16cd636a9c985_19)] | | |

| ITEM | | | 1B. | | | [UNRESOLVED STAFF [removed: COMMENTS](#i00f6c772b2784a239fcaf48012a18d4d_22)] [added: COMMENTS](#i7163b5f722664d73b2f16cd636a9c985_22)] | | | [removed: [36](#i00f6c772b2784a239fcaf48012a18d4d_22)] [added: [42](#i7163b5f722664d73b2f16cd636a9c985_22)] | | |

| ITEM | | | 1C. | | | [removed: [CYBERSECURITY](#i00f6c772b2784a239fcaf48012a18d4d_25)] [added: [CYBERSECURITY](#i7163b5f722664d73b2f16cd636a9c985_25)] | | | [removed: [36](#i00f6c772b2784a239fcaf48012a18d4d_25)] [added: [42](#i7163b5f722664d73b2f16cd636a9c985_25)] | | |

| ITEM | | | 2. | | | [removed: [PROPERTIES](#i00f6c772b2784a239fcaf48012a18d4d_28)] [added: [PROPERTIES](#i7163b5f722664d73b2f16cd636a9c985_28)] | | | [removed: [37](#i00f6c772b2784a239fcaf48012a18d4d_28)] [added: [43](#i7163b5f722664d73b2f16cd636a9c985_28)] | | |

| ITEM | | | 3. | | | [LEGAL [removed: PROCEEDINGS](#i00f6c772b2784a239fcaf48012a18d4d_31)] [added: PROCEEDINGS](#i7163b5f722664d73b2f16cd636a9c985_31)] | | | [removed: [37](#i00f6c772b2784a239fcaf48012a18d4d_31)] [added: [43](#i7163b5f722664d73b2f16cd636a9c985_31)] | | |

| ITEM | | | 4. | | | [MINE SAFETY [removed: DISCLOSURES](#i00f6c772b2784a239fcaf48012a18d4d_34)] [added: DISCLOSURES](#i7163b5f722664d73b2f16cd636a9c985_34)] | | | [removed: [38](#i00f6c772b2784a239fcaf48012a18d4d_34)] [added: [43](#i7163b5f722664d73b2f16cd636a9c985_34)] | | |

| ITEM | | | 5. | | | [MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY [removed: SECURITIES](#i00f6c772b2784a239fcaf48012a18d4d_40)] [added: SECURITIES](#i7163b5f722664d73b2f16cd636a9c985_40)] | | | [removed: [39](#i00f6c772b2784a239fcaf48012a18d4d_40)] [added: [44](#i7163b5f722664d73b2f16cd636a9c985_40)] | | |

| ITEM | | | 7. | | | [MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF [removed: OPERATIONS](#i00f6c772b2784a239fcaf48012a18d4d_43)] [added: OPERATIONS](#i7163b5f722664d73b2f16cd636a9c985_43)] | | | [removed: [41](#i00f6c772b2784a239fcaf48012a18d4d_43)] [added: [46](#i7163b5f722664d73b2f16cd636a9c985_43)] | | |

| ITEM | | | 7A. | | | [QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET [removed: RISK](#i00f6c772b2784a239fcaf48012a18d4d_61)] [added: RISK](#i7163b5f722664d73b2f16cd636a9c985_61)] | | | [removed: [61](#i00f6c772b2784a239fcaf48012a18d4d_61)] [added: [65](#i7163b5f722664d73b2f16cd636a9c985_61)] | | |

| ITEM | | | 8. | | | [FINANCIAL STATEMENTS AND SUPPLEMENTARY [removed: DATA](#i00f6c772b2784a239fcaf48012a18d4d_64)] [added: DATA](#i7163b5f722664d73b2f16cd636a9c985_64)] | | | [removed: [62](#i00f6c772b2784a239fcaf48012a18d4d_64)] [added: [66](#i7163b5f722664d73b2f16cd636a9c985_64)] | | |

| ITEM | | | 9. | | | [CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL [removed: DISCLOSURE](#i00f6c772b2784a239fcaf48012a18d4d_166)] [added: DISCLOSURE](#i7163b5f722664d73b2f16cd636a9c985_166)] | | | [removed: [114](#i00f6c772b2784a239fcaf48012a18d4d_166)] [added: [119](#i7163b5f722664d73b2f16cd636a9c985_166)] | | |

| ITEM | | | 9A. | | | [CONTROLS AND [removed: PROCEDURES](#i00f6c772b2784a239fcaf48012a18d4d_169)] [added: PROCEDURES](#i7163b5f722664d73b2f16cd636a9c985_169)] | | | [removed: [114](#i00f6c772b2784a239fcaf48012a18d4d_169)] [added: [119](#i7163b5f722664d73b2f16cd636a9c985_169)] | | |

| ITEM | | | 9B. | | | [OTHER [removed: INFORMATION](#i00f6c772b2784a239fcaf48012a18d4d_172)] [added: INFORMATION](#i7163b5f722664d73b2f16cd636a9c985_172)] | | | [removed: [116](#i00f6c772b2784a239fcaf48012a18d4d_172)] [added: [121](#i7163b5f722664d73b2f16cd636a9c985_172)] | | |

| ITEM | | | 9C. | | | [DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT [removed: INSPECTIONS](#i00f6c772b2784a239fcaf48012a18d4d_175)] [added: INSPECTIONS](#i7163b5f722664d73b2f16cd636a9c985_175)] | | | [removed: [116](#i00f6c772b2784a239fcaf48012a18d4d_175)] [added: [121](#i7163b5f722664d73b2f16cd636a9c985_175)] | | |

| ITEM | | | 10. | | | [DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE [removed: GOVERNANCE](#i00f6c772b2784a239fcaf48012a18d4d_181)] [added: GOVERNANCE](#i7163b5f722664d73b2f16cd636a9c985_181)] | | | [removed: [117](#i00f6c772b2784a239fcaf48012a18d4d_181)] [added: [122](#i7163b5f722664d73b2f16cd636a9c985_181)] | | |

| ITEM | | | 11. | | | [EXECUTIVE [removed: COMPENSATION](#i00f6c772b2784a239fcaf48012a18d4d_184)] [added: COMPENSATION](#i7163b5f722664d73b2f16cd636a9c985_184)] | | | [removed: [117](#i00f6c772b2784a239fcaf48012a18d4d_184)] [added: [122](#i7163b5f722664d73b2f16cd636a9c985_184)] | | |

| ITEM | | | 12. | | | [SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER [removed: MATTERS](#i00f6c772b2784a239fcaf48012a18d4d_187)] [added: MATTERS](#i7163b5f722664d73b2f16cd636a9c985_187)] | | | [removed: [117](#i00f6c772b2784a239fcaf48012a18d4d_187)] [added: [122](#i7163b5f722664d73b2f16cd636a9c985_187)] | | |

| ITEM | | | 13. | | | [CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR [removed: INDEPENDENCE](#i00f6c772b2784a239fcaf48012a18d4d_190)] [added: INDEPENDENCE](#i7163b5f722664d73b2f16cd636a9c985_190)] | | | [removed: [117](#i00f6c772b2784a239fcaf48012a18d4d_190)] [added: [122](#i7163b5f722664d73b2f16cd636a9c985_190)] | | |

| ITEM | | | 14. | | | [PRINCIPAL ACCOUNTANT FEES AND [removed: SERVICES](#i00f6c772b2784a239fcaf48012a18d4d_193)] [added: SERVICES](#i7163b5f722664d73b2f16cd636a9c985_193)] | | | [removed: [117](#i00f6c772b2784a239fcaf48012a18d4d_193)] [added: [122](#i7163b5f722664d73b2f16cd636a9c985_193)] | | |

| ITEM | | | 15. | | | [EXHIBITS AND FINANCIAL STATEMENT [removed: SCHEDULES](#i00f6c772b2784a239fcaf48012a18d4d_199)] [added: SCHEDULES](#i7163b5f722664d73b2f16cd636a9c985_199)] | | | [removed: [118](#i00f6c772b2784a239fcaf48012a18d4d_199)] [added: [123](#i7163b5f722664d73b2f16cd636a9c985_199)] | | |

| ITEM | | | 16. | | | [FORM 10-K [removed: SUMMARY](#i00f6c772b2784a239fcaf48012a18d4d_7)] [added: SUMMARY](#i7163b5f722664d73b2f16cd636a9c985_7)] | | | [removed: [122](#i00f6c772b2784a239fcaf48012a18d4d_208)] [added: [127](#i7163b5f722664d73b2f16cd636a9c985_208)] | | |

| EX-21 | | | | | | [LIST OF COMPANIES AND [removed: SUBSIDIARIES](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb1231202410-kex21.htm)] [added: SUBSIDIARIES](https://www.sec.gov/Archives/edgar/data/11544/000001154426000005/wrb1231202510-kex21.htm)] | | | | | |

| EX-23 | | | | | | [CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING [removed: FIRM](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb1231202410-kex23.htm)] [added: FIRM](https://www.sec.gov/Archives/edgar/data/11544/000001154426000005/wrb1231202510-kex23.htm)] | | | | | |

| EX-31.1 | | | | | | [CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER PURSUANT TO RULE 13a-14(a) [removed: /15d-14(a)](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb1231202410-kex311.htm)] [added: /15d-14(a)](https://www.sec.gov/Archives/edgar/data/11544/000001154426000005/wrb1231202510-kex311.htm)] | | | | | |

| EX-31.2 | | | | | | [CERTIFICATION OF THE CHIEF FINANCIAL OFFICER PURSUANT TO RULE 13a-14(a) [removed: /15d-14(a)](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb1231202410-kex312.htm)] [added: /15d-14(a)](https://www.sec.gov/Archives/edgar/data/11544/000001154426000005/wrb1231202510-kex312.htm)] | | | | | |

| EX-32.1 | | | | | | [CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF [removed: 2002](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb1231202410-kex321.htm)] [added: 2002](https://www.sec.gov/Archives/edgar/data/11544/000001154426000005/wrb1231202510-kex321.htm)] | | | | | |

Any forward-looking statements contained in this report including statements related to our outlook for the industry and for our performance for the year [removed: 2025] [added: 2026] and beyond, are based upon our historical performance and on current plans, estimates and expectations.

- investment risks, including those of our portfolio of fixed maturity securities and investments in equity securities, including investments in financial institutions, municipal bonds, [added: foreign government bonds,] mortgage-backed securities, loans receivable, investment funds, including real estate, merger arbitrage, energy-related and private equity investments;

- general economic and market activities, including inflation, interest [removed: rates] [added: rates, tariffs] and volatility in the credit and capital markets;

- the [added: increasing] use of artificial intelligence technologies by us or third-parties on which we rely could expose us to technological, security, legal, and other risks;

These risks and uncertainties could cause our actual results for the year [removed: 2025] [added: 2026] and beyond to differ materially from those expressed in any forward-looking statement we make.

| EX-4.1 | | | | | | [DESCRIPTION OF REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934](https://www.sec.gov/Archives/edgar/data/11544/000001154426000005/wrb1231202510-kex41.htm) | | | | | |

| | | | | | | | | | | | |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| EX-19.1 | | | | | | [INSIDER TRADING POLICY](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb12312024ex191insidertra.htm) | | | | | |

The Program is designed to protect the confidentiality, integrity and availability of our information systems and assets that store, process, or transmit [removed: information.][added: information, as well as the information processed thereon.]

The Program is modeled on the global standard for [removed: risk assessment,] [added: information security management systems,] International Organization for Standardization 27001, and is guided by the six domains of cybersecurity established by the National Institute of Standards and Technology Cybersecurity Framework (i.e., govern, identify, protect, detect, respond, and recovery).

–vulnerability management, including penetration and control testing and vulnerability scans of information [removed: systems;][added: systems, and patching of systems when vulnerabilities have been identified;]

–incident monitoring, breach notification and [removed: escalation,] [added: escalation procedures,] including disaster recovery and incident response plans and resources;

Collectively, the CISO and RISOs, along with their teams, in collaboration with the technology and business owners, [removed: implement the Program.]

implement the Program.

At December 31, [removed: 2024,] [added: 2025,] the Company had aggregate office space of [removed: 4,177,891] [added: 4,068,719] square feet, of which [removed: 1,051,681] [added: 1,093,057] were owned and [removed: 3,126,210] [added: 2,975,662] were leased.

Rental expense for the Company's operations was approximately [removed: $45,718,000, $44,256,000] [added: $54,261,000, $45,718,000] and [removed: $43,383,000] [added: $44,256,000] for [removed: 2024, 2023] [added: 2025, 2024] and [removed: 2022,] [added: 2023,] respectively.

Future minimum lease payments, without provision for sublease income, are [removed: $48,822,000] [added: $54,475,000] in [removed: 2025, $41,861,000] [added: 2026, $47,249,000] in [removed: 2026] [added: 2027] and [removed: $172,679,000] [added: $220,860,000] thereafter.

In [removed: 2024,] [added: 2025,] the Board declared [removed: regular] [added: ordinary] quarterly cash dividends of [removed: $0.07] [added: $0.08] per share in the first quarter and [removed: $0.08] [added: $0.09] per share in each of the remaining three quarters, as well as special dividends of [removed: $0.33 per share, $0.25] [added: $0.50] per share and [removed: $0.50] [added: $1.00] per share in the [removed: second, third,] [added: second] and fourth quarters, [added: respectively,] for a total of [removed: $532] [added: $700] million in aggregate dividends in [removed: 2024.][added: 2025.]

The approximate number of record holders of the common stock on February [removed: 13, 2025] [added: 23, 2026] was [removed: 327.][added: 312.]

*Assumes initial investment of $100 on January 1, [removed: 2019,] [added: 2020,] with dividends reinvested.*

[removed: ][added: ]

As of December 31, [removed: 2024,] [added: 2025,] the S&P 500® Property and Casualty Insurance Index consisted of The Allstate Corporation, Arch Capital Group Ltd. (added Nov.

| | | | | | | [removed: 2019 | | |] 2020 | | | 2021 | | | 2022 | | | 2023 | | | 2024 | | | [added: 2025 | | |]

| S&P 500 Property and Casualty Insurance Index | | | Cum $ | | | 100.00 | | | [removed: 106.33] [added: 117.51] | | | [removed: 124.95] [added: 139.75] | | | [removed: 148.60] [added: 154.81] | | | [removed: 164.61] [added: 208.84] | | | [removed: 222.06] [added: 228.45] | | |

Set forth below is a summary of the shares repurchased by the Company during the fourth quarter of [removed: 2024] [added: 2025] and the remaining number of shares authorized for purchase by the Company during such period.

| | | | Total Number of Shares Purchased | | | | | | Average Price Paid per Share | | | | | | Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs | | | | | | Maximum Number of Shares that may yet be Purchased Under the Plans or [removed: Programs] [added: Programs (1)] | | |

| W. R. Berkley Corporation | | | Cum $ | | | 100.00 | | | 127.33 | | | 170.47 | | | 170.88 | | | 217.34 | | | 267.30 | | |

| S&P 500 Index - Total Returns | | | Cum $ | | | 100.00 | | | 128.68 | | | 105.30 | | | 133.03 | | | 165.98 | | | 195.63 | | |

| October 2025 | | | 285,635 | | | | | | $ | 70.99 | | | | | 285,635 | | | | | | 12,673,293 | | |

| November 2025 | | | 85,533 | | | | | | 71.02 | | | | | | 85,533 | | | | | | 12,587,760 | | |

| December 2025 | | | 2,497,858 | | | | | | 68.07 | | | | | | 2,497,858 | | | | | | 10,089,902 | | |

(1) The Company's repurchase authorization was increased to 25,000,000 shares on January 8, 2026.

| W. R. Berkley Corporation | | | Cum $ | | | 100.00 | | | 96.85 | | | 123.32 | | | 165.10 | | | 165.50 | | | 210.49 | | |

| S&P 500 Index - Total Returns | | | Cum $ | | | 100.00 | | | 118.38 | | | 152.33 | | | 124.65 | | | 157.48 | | | 196.49 | | |

| October 2024 | | | 715,920 | | | | | | $ | 57.91 | | | | | 715,920 | | | | | | 14,608,875 | | |

| November 2024 | | | 449,947 | | | | | | 57.69 | | | | | | 449,947 | | | | | | 14,158,928 | | |

| December 2024 | | | — | | | | | | — | | | | | | — | | | | | | 14,158,928 | | |

We have audited the accompanying consolidated balance sheets of W. R. Berkley Corporation and subsidiaries (the Company) as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] the related consolidated statements of income, comprehensive income, stockholders’ equity, and cash flows for each of the years in the three‑year period ended December 31, [removed: 2024,] [added: 2025,] and the related notes and financial statement schedules II to VI (collectively, the consolidated financial statements).

In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, [removed: 2024,] [added: 2025,] in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in *Internal Control - Integrated Framework (2013)* issued by the Committee of Sponsoring Organizations of the Treadway Commission, and our report dated February [removed: 24, 2025] [added: 27, 2026] expressed an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.

The reserves as of December 31, [removed: 2024] [added: 2025] were [removed: $20.4] [added: $22.2] billion.

| (In thousands, except per share data) | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | |

| Net premiums written | | | $ | [removed: 11,972,096] [added: 12,711,327] | | | | | $ | [removed: 10,954,467] [added: 11,972,096] | | | | | $ | [removed: 10,004,070] [added: 10,954,467] | |

| Change in net unearned premiums | | | [removed: (423,611)] [added: (264,389)] | | | | | | [removed: (553,780)] [added: (423,611)] | | | | | | [removed: (442,641)] [added: (553,780)] | | |

| Net premiums earned | | | [removed: 11,548,485] [added: 12,446,938] | | | | | | [removed: 10,400,687] [added: 11,548,485] | | | | | | [removed: 9,561,429] [added: 10,400,687] | | |

| Net investment income | | | [removed: 1,333,161] [added: 1,429,067] | | | | | | [removed: 1,052,835] [added: 1,333,161] | | | | | | [removed: 779,185] [added: 1,052,835] | | |

| Net realized and unrealized gains on investments | | | [removed: 79,738] [added: 130,670] | | | | | | [removed: 47,540] [added: 79,738] | | | | | | [removed: 217,311] [added: 47,540] | | |

| Change in allowance for expected credit losses on investments | | | [removed: 37,970] [added: 1,550] | | | | | | [removed: (498)] [added: 37,970] | | | | | | [removed: (14,914)] [added: (498)] | | |

| Net investment gains | | | [removed: 117,708] [added: 132,220] | | | | | | [removed: 47,042] [added: 117,708] | | | | | | [removed: 202,397] [added: 47,042] | | |

| Revenues from non-insurance businesses | | | [removed: 528,012] [added: 577,420] | | | | | | [removed: 535,508] [added: 528,012] | | | | | | [removed: 509,548] [added: 535,508] | | |

| Insurance service fees | | | [removed: 108,935] [added: 118,511] | | | | | | [removed: 106,485] [added: 108,935] | | | | | | [removed: 110,544] [added: 106,485] | | |

| Other income | | | [removed: 2,451] [added: 3,700] | | | | | | [removed: 381] [added: 2,451] | | | | | | [removed: 3,396] [added: 381] | | |

| Total revenues | | | [removed: 13,638,752] [added: 14,707,856] | | | | | | [removed: 12,142,938] [added: 13,638,752] | | | | | | [removed: 11,166,499] [added: 12,142,938] | | |

| Losses and loss expenses | | | [removed: 7,131,595] [added: 7,771,657] | | | | | | [removed: 6,372,142] [added: 7,131,595] | | | | | | [removed: 5,861,750] [added: 6,372,142] | | |

| Other operating costs and expenses | | | [removed: 3,602,306] [added: 3,976,834] | | | | | | [removed: 3,363,936] [added: 3,602,306] | | | | | | [removed: 2,961,505] [added: 3,363,936] | | |

| Expenses from non-insurance businesses | | | [removed: 513,451] [added: 551,930] | | | | | | [removed: 524,998] [added: 513,451] | | | | | | [removed: 493,189] [added: 524,998] | | |

| Interest expense | | | [removed: 126,907] [added: 126,892] | | | | | | [removed: 127,459] [added: 126,907] | | | | | | [removed: 130,374] [added: 127,459] | | |

| Total operating costs and expenses | | | [removed: 11,374,259] [added: 12,427,313] | | | | | | [removed: 10,388,535] [added: 11,374,259] | | | | | | [removed: 9,446,818] [added: 10,388,535] | | |

| Income before income taxes | | | [removed: 2,264,493] [added: 2,280,543] | | | | | | [removed: 1,754,403] [added: 2,264,493] | | | | | | [removed: 1,719,681] [added: 1,754,403] | | |

| Income tax expense | | | [removed: (509,916)] [added: (495,764)] | | | | | | [removed: (370,557)] [added: (509,916)] | | | | | | [removed: (334,727)] [added: (370,557)] | | |

| Net income before noncontrolling interests | | | [removed: 1,754,577] [added: 1,784,779] | | | | | | [removed: 1,383,846] [added: 1,754,577] | | | | | | [removed: 1,384,954] [added: 1,383,846] | | |

| Noncontrolling interests | | | [removed: 1,538] [added: (5,376)] | | | | | | [removed: (2,487)] [added: 1,538] | | | | | | [removed: (3,892)] [added: (2,487)] | | |

| Net income to common stockholders | | | $ | [removed: 1,756,115] [added: 1,779,403] | | | | | $ | [removed: 1,381,359] [added: 1,756,115] | | | | | $ | [removed: 1,381,062] [added: 1,381,359] | |

| Basic | | | $ | [removed: 4.39] [added: 4.48] | | | | | $ | [removed: 3.40] [added: 4.39] | | | | | $ | [removed: 3.33] [added: 3.40] | |

| Diluted | | | $ | [removed: 4.36] [added: 4.45] | | | | | $ | [removed: 3.37] [added: 4.36] | | | | | $ | [removed: 3.29] [added: 3.37] | |

| (In thousands) | | | [removed: 2024] [added: 2025] | | | | | | [removed: 2023] [added: 2024] | | | | | | [removed: 2022] [added: 2023] | | |

| Net income before noncontrolling interests | | | $ | [removed: 1,754,577] [added: 1,784,779] | | | | | $ | [removed: 1,383,846] [added: 1,754,577] | | | | | $ | [removed: 1,384,954] [added: 1,383,846] | |

| Other comprehensive [removed: (loss) gain:] [added: gain (loss):] | | | | | | | | | | | | | | | | | |

| Change in unrealized translation adjustments | | | [removed: (77,615)] [added: 90,682] | | | | | | [removed: 32,192] [added: (77,615)] | | | | | | [removed: 1,179] [added: 32,192] | | |

| Change in unrealized investment [removed: gains (losses),] [added: gains,] net of taxes | | | [removed: 69,182] [added: 392,491] | | | | | | [removed: 306,553] [added: 69,182] | | | | | | [removed: (983,803)] [added: 306,553] | | |

| Other comprehensive [removed: (loss)] gain [added: (loss)] | | | [removed: (8,433)] [added: 483,173] | | | | | | [removed: 338,745] [added: (8,433)] | | | | | | [removed: (982,624)] [added: 338,745] | | |

| Comprehensive income | | | [removed: 1,746,144] [added: 2,267,952] | | | | | | [removed: 1,722,591] [added: 1,746,144] | | | | | | [removed: 402,330] [added: 1,722,591] | | |

| Noncontrolling interests | | | [removed: 1,536] [added: (5,375)] | | | | | | [removed: (2,485)] [added: 1,536] | | | | | | [removed: (3,890)] [added: (2,485)] | | |

| Comprehensive income to common stockholders | | | $ | [removed: 1,747,680] [added: 2,262,577] | | | | | $ | [removed: 1,720,106] [added: 1,747,680] | | | | | $ | [removed: 398,440] [added: 1,720,106] | |

| (In thousands, except [added: per] share data) | | | [added: | | | | | | | | | | | | | | | | | | 2025 | | | | | |] 2024 | | | | | | 2023 | | |

| Fixed maturity securities (amortized cost of [removed: $23,010,899] [added: $25,170,368] and [removed: $20,915,245;] [added: $23,010,899;] allowance for expected credit losses of [removed: $671] [added: $74] and [removed: $36,751] [added: $671] at December 31, [removed: 2024] [added: 2025] and [removed: 2023)] [added: 2024)] | | | $ | [removed: 22,397,865] [added: 25,047,662] | | | | | $ | [removed: 20,178,308] [added: 22,397,865] | |

| Investment funds | | | [removed: 1,468,246] [added: 1,361,802] | | | | | | [removed: 1,621,655] [added: 1,468,246] | | |

February 27, 2026

| Net income to common stockholders | | | $ | 1,779,403 | | | | | $ | 1,756,115 | | | | | $ | 1,381,359 | |

Income taxes paid were $407 million (including $340 million to the United States, $40 million to Australia and $27 million to other jurisdictions), $410 million (including $361 million to the United States, $25 million to Australia and $24 million to other jurisdictions) and $332 million (including $296 million to the United States, $18 million to Australia and $18 million to other jurisdictions) in 2025, 2024 and 2023, respectively.

In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update 2023-09, Improvements to Income Tax Disclosures (Topic 740), to enhance the transparency and usefulness of income tax disclosures.

The guidance requires additional disclosures primarily related to the rate reconciliation and income taxes paid.

This guidance is effective for annual periods beginning after December 15, 2024.

All other accounting and reporting standards that became effective in 2025 were either not applicable to the Company or their adoption did not have a material impact on the Company.

In November 2024, the Financial Accounting Standards Board issued Accounting Standards Update 2024-03, Disaggregation of Income Statement Expenses, addressing investor requests for more transparent information.

The guidance requires disclosure of specified information about certain costs and expenses in the notes to the financial statements.

Prospective application is required, with retrospective application permitted.

The Company will adopt this guidance for the year ended December 31, 2027 and resulting impact will be disclosure only.

| Beginning of period | | | $ | (517,170) | | | | | $ | (417,099) | | | | | | | | | | | $ | (934,269) | |

| Other comprehensive income before reclassifications | | | 344,083 | | | | | | 90,682 | | | | | | | | | | | | 434,765 | | |

| Other comprehensive income | | | 392,491 | | | | | | 90,682 | | | | | | | | | | | | 483,173 | | |

| Ending balance | | | $ | (124,680) | | | | | $ | (326,417) | | | | | | | | | | | $ | (451,097) | |

| Pre-tax | | | $ | 497,765 | | | | | $ | 90,682 | | | | | | | | | | | $ | 588,447 | |

| Other comprehensive income | | | $ | 392,491 | | | | | $ | 90,682 | | | | | | | | | | | $ | 483,173 | |

| December 31, 2025 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| State and municipal | | | $ | 28,777 | | | | | $ | (9) | | | | | $ | 796 | | | | | $ | — | | | | | $ | 29,564 | | | | | $ | 28,768 | | | | | | | |

| Residential mortgage-backed | | | 1,838 | | | | | | — | | | | | | 76 | | | | | | — | | | | | | 1,914 | | | | | | 1,838 | | | | | | | | |

| Total held to maturity | | | 30,615 | | | | | | (9) | | | | | | 872 | | | | | | — | | | | | | 31,478 | | | | | | 30,606 | | | | | | | | |

| U.S. government and government agency | | | 3,964,375 | | | | | | — | | | | | | 48,820 | | | | | | (15,157) | | | | | | 3,998,038 | | | | | | 3,998,038 | | | | | | | | |

| Special revenue | | | 1,206,387 | | | | | | — | | | | | | 6,002 | | | | | | (27,943) | | | | | | 1,184,446 | | | | | | 1,184,446 | | | | | | | | |

| State general obligation | | | 203,543 | | | | | | — | | | | | | 3,465 | | | | | | (3,848) | | | | | | 203,160 | | | | | | 203,160 | | | | | | | | |

| Pre-refunded | | | 74,276 | | | | | | — | | | | | | 619 | | | | | | (111) | | | | | | 74,784 | | | | | | 74,784 | | | | | | | | |

| Corporate backed | | | 159,876 | | | | | | — | | | | | | 1,958 | | | | | | (3,459) | | | | | | 158,375 | | | | | | 158,375 | | | | | | | | |

| Local general obligation | | | 218,022 | | | | | | — | | | | | | 1,459 | | | | | | (3,052) | | | | | | 216,429 | | | | | | 216,429 | | | | | | | | |

| Total state and municipal | | | 1,862,104 | | | | | | — | | | | | | 13,503 | | | | | | (38,413) | | | | | | 1,837,194 | | | | | | 1,837,194 | | | | | | | | |

| Residential | | | 4,584,970 | | | | | | (65) | | | | | | 71,048 | | | | | | (132,645) | | | | | | 4,523,308 | | | | | | 4,523,308 | | | | | | | | |

| Commercial | | | 281,573 | | | | | | — | | | | | | 3,632 | | | | | | (35) | | | | | | 285,170 | | | | | | 285,170 | | | | | | | | |

| Total mortgage-backed securities | | | 4,866,543 | | | | | | (65) | | | | | | 74,680 | | | | | | (132,680) | | | | | | 4,808,478 | | | | | | 4,808,478 | | | | | | | | |

| Asset-backed securities | | | 3,807,393 | | | | | | — | | | | | | 20,196 | | | | | | (17,243) | | | | | | 3,810,346 | | | | | | 3,810,346 | | | | | | | | |

| Industrial | | | 3,627,567 | | | | | | — | | | | | | 57,466 | | | | | | (36,499) | | | | | | 3,648,534 | | | | | | 3,648,534 | | | | | | | | |

| Financial | | | 3,438,348 | | | | | | — | | | | | | 61,180 | | | | | | (16,460) | | | | | | 3,483,068 | | | | | | 3,483,068 | | | | | | | | |

| Utilities | | | 1,300,506 | | | | | | — | | | | | | 22,593 | | | | | | (8,878) | | | | | | 1,314,221 | | | | | | 1,314,221 | | | | | | | | |

| Other | | | 240,374 | | | | | | — | | | | | | 2,356 | | | | | | (1,142) | | | | | | 241,588 | | | | | | 241,588 | | | | | | | | |

| Total corporate | | | 8,606,795 | | | | | | — | | | | | | 143,595 | | | | | | (62,979) | | | | | | 8,687,411 | | | | | | 8,687,411 | | | | | | | | |

| Foreign government | | | 2,032,543 | | | | | | — | | | | | | 20,906 | | | | | | (177,860) | | | | | | 1,875,589 | | | | | | 1,875,589 | | | | | | | | |

| Total available for sale | | | 25,139,753 | | | | | | (65) | | | | | | 321,700 | | | | | | (444,332) | | | | | | 25,017,056 | | | | | | 25,017,056 | | | | | | | | |

| Total investments in fixed maturity securities | | | $ | 25,170,368 | | | | | $ | (74) | | | | | $ | 322,572 | | | | | $ | (444,332) | | | | | $ | 25,048,534 | | | | | $ | 25,047,662 | | | | | | | |

February 24, 2025

| Cash and cash equivalents at beginning of year | | | 1,363,195 | | | | | | 1,449,346 | | | | | | 1,568,843 | | |

Income taxes paid were $410 million, $332 million and $295 million in 2024, 2023 and 2022, respectively.

In November 2023, the Financial Accounting Standards Board issued ASU 2023-07, *Improvements to Reportable Segment Disclosures*, which enhances current segment disclosures and requires additional disclosures of significant segment expenses.

When applying this disclosure requirement, an entity identifies the significant expenses for each reportable segment that are regularly provided to its chief operating decision maker and included in the reported measures of a segment’s profit or loss.

| Beginning of period | | | $ | (892,905) | | | | | $ | (371,676) | | | | | | | | | | | $ | (1,264,581) | |

| Other comprehensive income before reclassifications | | | 252,782 | | | | | | 32,192 | | | | | | | | | | | | 284,974 | | |

| Other comprehensive income | | | 306,553 | | | | | | 32,192 | | | | | | | | | | | | 338,745 | | |

| Ending balance | | | $ | (586,354) | | | | | $ | (339,484) | | | | | | | | | | | $ | (925,838) | |

| Pre-tax | | | $ | 392,903 | | | | | $ | 32,192 | | | | | | | | | | | $ | 425,095 | |

| Other comprehensive income | | | $ | 306,553 | | | | | $ | 32,192 | | | | | | | | | | | $ | 338,745 | |

| December 31, 2023 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| State and municipal | | | $ | 50,547 | | | | | $ | (43) | | | | | $ | 3,132 | | | | | $ | — | | | | | $ | 53,636 | | | | | $ | 50,504 | |

| Residential mortgage-backed | | | 2,868 | | | | | | — | | | | | | 107 | | | | | | — | | | | | | 2,975 | | | | | | 2,868 | | |

| Total held to maturity | | | 53,415 | | | | | | (43) | | | | | | 3,239 | | | | | | — | | | | | | 56,611 | | | | | | 53,372 | | |

| U.S. government and government agency | | | 1,762,997 | | | | | | — | | | | | | 11,403 | | | | | | (57,669) | | | | | | 1,716,731 | | | | | | 1,716,731 | | |

| Special revenue | | | 1,682,550 | | | | | | — | | | | | | 5,651 | | | | | | (82,006) | | | | | | 1,606,195 | | | | | | 1,606,195 | | |

| State general obligation | | | 394,429 | | | | | | — | | | | | | 3,550 | | | | | | (16,405) | | | | | | 381,574 | | | | | | 381,574 | | |

| Pre-refunded | | | 103,029 | | | | | | — | | | | | | 1,634 | | | | | | (185) | | | | | | 104,478 | | | | | | 104,478 | | |

| Corporate backed | | | 166,873 | | | | | | (757) | | | | | | 696 | | | | | | (11,973) | | | | | | 154,839 | | | | | | 154,839 | | |

| Local general obligation | | | 396,041 | | | | | | — | | | | | | 3,188 | | | | | | (11,893) | | | | | | 387,336 | | | | | | 387,336 | | |

| Total state and municipal | | | 2,742,922 | | | | | | (757) | | | | | | 14,719 | | | | | | (122,462) | | | | | | 2,634,422 | | | | | | 2,634,422 | | |

| Residential | | | 1,773,206 | | | | | | — | | | | | | 12,780 | | | | | | (163,844) | | | | | | 1,622,142 | | | | | | 1,622,142 | | |

| Commercial | | | 657,157 | | | | | | (158) | | | | | | 626 | | | | | | (13,312) | | | | | | 644,313 | | | | | | 644,313 | | |

| Total mortgage-backed securities | | | 2,430,363 | | | | | | (158) | | | | | | 13,406 | | | | | | (177,156) | | | | | | 2,266,455 | | | | | | 2,266,455 | | |

| Asset-backed securities | | | 4,252,883 | | | | | | (1,164) | | | | | | 8,527 | | | | | | (73,206) | | | | | | 4,187,040 | | | | | | 4,187,040 | | |

| Industrial | | | 3,679,219 | | | | | | (40) | | | | | | 24,312 | | | | | | (143,936) | | | | | | 3,559,555 | | | | | | 3,559,555 | | |

| Financial | | | 2,838,220 | | | | | | (4,986) | | | | | | 14,681 | | | | | | (68,681) | | | | | | 2,779,234 | | | | | | 2,779,234 | | |

| Utilities | | | 701,865 | | | | | | — | | | | | | 6,471 | | | | | | (23,412) | | | | | | 684,924 | | | | | | 684,924 | | |

| Other | | | 635,975 | | | | | | — | | | | | | 1,605 | | | | | | (7,234) | | | | | | 630,346 | | | | | | 630,346 | | |

| Total corporate | | | 7,855,279 | | | | | | (5,026) | | | | | | 47,069 | | | | | | (243,263) | | | | | | 7,654,059 | | | | | | 7,654,059 | | |

| Foreign government | | | 1,817,386 | | | | | | (29,603) | | | | | | 15,865 | | | | | | (137,419) | | | | | | 1,666,229 | | | | | | 1,666,229 | | |

| Total available for sale | | | 20,861,830 | | | | | | (36,708) | | | | | | 110,989 | | | | | | (811,175) | | | | | | 20,124,936 | | | | | | 20,124,936 | | |

| Total investments in fixed maturity securities | | | $ | 20,915,245 | | | | | $ | (36,751) | | | | | $ | 114,228 | | | | | $ | (811,175) | | | | | $ | 20,181,547 | | | | | $ | 20,178,308 | |

| Due in one year or less | | | $ | 1,744,361 | | | | | $ | 1,719,948 | |

| Due after ten years | | | 4,013,827 | | | | | | 3,949,220 | | |

| Mortgage-backed securities | | | 3,949,024 | | | | | | 3,767,851 | | |

| Total | | | $ | 23,010,874 | | | | | $ | 22,399,426 | |

| December 31, 2023 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| Common stocks | | | $ | 664,997 | | | | | $ | 191,806 | | | | | $ | (18,749) | | | | | $ | 838,054 | | | | | $ | 838,054 | |

During the quarter ended December 31, [removed: 2024,] [added: 2025,] there were no changes in our internal controls over financial reporting that have materially affected, or are reasonably likely to materially affect, our internal controls over financial reporting.

Based on our evaluation under the framework in Internal Control - Integrated Framework, our management concluded that our internal control over financial reporting was effective as of December 31, [removed: 2024.][added: 2025.]

We have audited W. R. Berkley Corporation and subsidiaries’ (the Company) internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in *Internal Control - Integrated Framework (2013)* issued by the Committee of Sponsoring Organizations of the Treadway Commission.

In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, [removed: 2024,] [added: 2025,] based on criteria established in *Internal Control - Integrated Framework (2013)* issued by the Committee of Sponsoring Organizations of the Treadway Commission.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated balance sheets of the Company as of December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] the related consolidated statements of income, comprehensive income, stockholders’ equity, and cash flows for each of the years in the three-year period ended December 31, [removed: 2024,] [added: 2025,] and the related notes and financial statement schedules II to VI (collectively, the consolidated financial statements), and our report dated February [removed: 24, 2025] [added: 27, 2026] expressed an unqualified opinion on those consolidated financial statements.

February 27, 2026

February 24, 2025

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, [removed: 2024,] [added: 2025,] and which is incorporated herein by reference.

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, [removed: 2024,] [added: 2025,] and which is incorporated herein by reference.

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, [removed: 2024,] [added: 2025,] and which is incorporated herein by reference.

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, 2025, and which is incorporated herein by reference.

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, 2025, and which is incorporated herein by reference.

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, 2025, and which is incorporated herein by reference.

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, [removed: 2024,] [added: 2025,] and which is incorporated herein by reference.

Reference is made to the registrant's definitive proxy statement, which will be filed with the Securities and Exchange Commission within 120 days after December 31, [removed: 2024,] [added: 2025,] and which is incorporated herein by reference.

| | | | [Schedule II — Condensed Financial Information of [removed: Registrant](#i00f6c772b2784a239fcaf48012a18d4d_214)] [added: Registrant](#i7163b5f722664d73b2f16cd636a9c985_214)] | | | [removed: [125](#i00f6c772b2784a239fcaf48012a18d4d_214)] [added: [130](#i7163b5f722664d73b2f16cd636a9c985_214)] | | |

| | | | [Schedule III — Supplementary Insurance [removed: Information](#i00f6c772b2784a239fcaf48012a18d4d_217)] [added: Information](#i7163b5f722664d73b2f16cd636a9c985_217)] | | | [removed: [129](#i00f6c772b2784a239fcaf48012a18d4d_217)] [added: [134](#i7163b5f722664d73b2f16cd636a9c985_217)] | | |

| | | | [Schedule IV — [removed: Reinsurance](#i00f6c772b2784a239fcaf48012a18d4d_220)] [added: Reinsurance](#i7163b5f722664d73b2f16cd636a9c985_220)] | | | [removed: [130](#i00f6c772b2784a239fcaf48012a18d4d_220)] [added: [135](#i7163b5f722664d73b2f16cd636a9c985_220)] | | |

| | | | [Schedule V — Valuation and Qualifying [removed: Accounts](#i00f6c772b2784a239fcaf48012a18d4d_223)] [added: Accounts](#i7163b5f722664d73b2f16cd636a9c985_223)] | | | [removed: [131](#i00f6c772b2784a239fcaf48012a18d4d_223)] [added: [136](#i7163b5f722664d73b2f16cd636a9c985_223)] | | |

| | | | [Schedule VI — Supplementary Information Concerning Property — Casualty Insurance [removed: Operations](#i00f6c772b2784a239fcaf48012a18d4d_226)] [added: Operations](#i7163b5f722664d73b2f16cd636a9c985_226)] | | | [removed: [132](#i00f6c772b2784a239fcaf48012a18d4d_226)] [added: [137](#i7163b5f722664d73b2f16cd636a9c985_226)] | | |

| [removed: ([3.1](http://www.sec.gov/Archives/edgar/data/11544/000095012303009001/y89010exv3w1.txt))] [added: ([3.1](https://www.sec.gov/Archives/edgar/data/11544/000095012303009001/y89010exv3w1.txt))] | | | The Company’s Restated Certificate of Incorporation, as amended through May 10, 2004 (incorporated by reference to Exhibits 3.1 and 3.2 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on August 6, 2003). | | |

| [removed: ([3.2](http://www.sec.gov/Archives/edgar/data/11544/000095012304009233/y99817exv3w2.htm))] [added: ([3.2](https://www.sec.gov/Archives/edgar/data/11544/000095012304009233/y99817exv3w2.htm))] | | | Amendment, dated May 11, 2004, to the Company’s Restated Certificate of Incorporation, as amended (incorporated by reference to Exhibit 3.2 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on August 5, 2004). | | |

| [removed: ([3.3](http://www.sec.gov/Archives/edgar/data/11544/000089914006000757/b051706b.txt))] [added: ([3.3](https://www.sec.gov/Archives/edgar/data/11544/000089914006000757/b051706b.txt))] | | | Amendment, dated May 16, 2006, to the Company’s Restated Certificate of Incorporation, as amended (incorporated by reference to Exhibit 3.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on May 17, 2006). | | |

| ([3.4](https://www.sec.gov/Archives/edgar/data/11544/000001154420000071/exhibit316122020.htm)) | | | Amendment, dated June 12, 2020, to the Company’s Restated Certificate of Incorporation, as amended (incorporated by reference to Exhibit 3.1 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on June 16, 2020). | | |

| [removed: [(3.5)](https://www.sec.gov/Archives/edgar/data/11544/000001154422000019/exhibit316152022.htm)] [added: ([3.5](https://www.sec.gov/Archives/edgar/data/11544/000001154422000019/exhibit316152022.htm))] | | | Amendment, dated June 15, 2022, to the Company’s Restated Certificate of Incorporation, as amended (incorporated by reference to Exhibit 3.1 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on June 16, 2022). | | |

| [removed: ([3.6](https://www.sec.gov/Archives/edgar/data/11544/000089914023000449/w022423b.htm))] [added: ([3.7](https://www.sec.gov/Archives/edgar/data/11544/000089914023000449/w022423b.htm))] | | | Amended and Restated By-Laws of the Company (incorporated by reference to Exhibit 3.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on March 1, 2023). | | |

| [removed: ([4.1](https://www.sec.gov/Archives/edgar/data/11544/000001154423000004/wrb1231202210-kex41.htm))] [added: ([19.1](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb12312024ex191insidertra.htm))] | | | [removed: Description of Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934] [added: Insider Trading Policy] (incorporated by reference to Exhibit [removed: 4.1] [added: 19.1] of the [removed: Company’s] [added: Company's] Annual Report on Form 10-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on February 24, [removed: 2023).] [added: 2025).] | | |

| [removed: ([4.2](http://www.sec.gov/Archives/edgar/data/11544/000095012303003655/y84583exv4w1.htm))] [added: ([4.2](https://www.sec.gov/Archives/edgar/data/11544/000095012303003655/y84583exv4w1.htm))] | | | Indenture, dated as of February 14, 2003, between the Company and The Bank of New York, as Trustee (incorporated by reference to Exhibit 4.1 of the Company’s Annual Report on Form 10-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on March 31, 2003). | | |

| [removed: ([4.3](http://www.sec.gov/Archives/edgar/data/11544/000095012307003012/y30637exv4w7.txt))] [added: ([4.3](https://www.sec.gov/Archives/edgar/data/11544/000095012307003012/y30637exv4w7.txt))] | | | Fifth Supplemental Indenture, dated as of February 9, 2007, between the Company and The Bank of New York, as Trustee, relating to $250,000,000 principal amount of the Company’s 6.250% Senior Notes due 2037, including the form of the Notes as Exhibit A (incorporated by reference to Exhibit 4.7 of the Company’s Annual Report on Form 10-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on March 1, 2007). | | |

| [removed: ([4.4](http://www.sec.gov/Archives/edgar/data/11544/000119312514297751/d767573dex42.htm))] [added: ([4.4](https://www.sec.gov/Archives/edgar/data/11544/000119312514297751/d767573dex42.htm))] | | | Ninth Supplemental Indenture, dated as of August 6, 2014, between the Company and The Bank of New York Mellon, as Trustee, relating to $350,000,000 principal amount of the Company’s 4.750% Senior Notes due 2044, including the form of the Notes as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company's Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on August 6, 2014). | | |

| [removed: ([4.5](http://www.sec.gov/Archives/edgar/data/11544/000119312520140282/d867995dex41.htm))] [added: ([4.5](https://www.sec.gov/Archives/edgar/data/11544/000119312520140282/d867995dex41.htm))] | | | Indenture, dated as of May 12, 2020, between the Company and The Bank of New York Mellon, as Trustee (incorporated by reference to Exhibit 4.1 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on May 12, 2020). | | |

| [removed: ([4.6](http://www.sec.gov/Archives/edgar/data/11544/000119312520140282/d867995dex42.htm))] [added: ([4.6](https://www.sec.gov/Archives/edgar/data/11544/000119312520140282/d867995dex42.htm))] | | | First Supplemental Indenture, dated as of May 12, 2020, between the Company and The Bank of New York Mellon, as Trustee, relating to $470,000,000 principal amount of the Company’s 4.000% Senior Notes due 2050, including the form of the Notes as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on May 12, 2020). | | |

| [removed: [(4.7)](https://www.sec.gov/Archives/edgar/data/0000011544/000119312521082861/d130286dex42.htm)] [added: ([4.7](https://www.sec.gov/Archives/edgar/data/0000011544/000119312521082861/d130286dex42.htm))] | | | Second Supplemental Indenture, dated as of March 16, 2021, between the Company and The Bank of New York Mellon, as Trustee, relating to $400,000,000 principal amount of the Company’s 3.550% Senior Notes due 2052, including the form of the Notes as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on March 16, 2021). | | |

| [removed: [(4.8)](https://www.sec.gov/Archives/edgar/data/0000011544/000119312521273619/d225177dex42.htm)] [added: ([4.8](https://www.sec.gov/Archives/edgar/data/0000011544/000119312521273619/d225177dex42.htm))] | | | Third Supplemental Indenture, dated as of September 15, 2021, between the Company and The Bank of New York Mellon, as Trustee, relating to $350,000,000 principal amount of the Company’s 3.150% Senior Notes due 2061, including the form of the Notes as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on September 15, 2021). | | |

| [removed: [(4.9)](https://www.sec.gov/Archives/edgar/data/11544/000119312518095381/d542041dex41.htm)] [added: ([4.9](https://www.sec.gov/Archives/edgar/data/11544/000119312518095381/d542041dex41.htm))] | | | Subordinated Indenture, dated as of March 26, 2018, between the Company and The Bank of New York Mellon, as Trustee (incorporated by reference to Exhibit 4.1 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on March 26, 2018). | | |

| [removed: [(4.10)](https://www.sec.gov/Archives/edgar/data/11544/000119312518095381/d542041dex42.htm)] [added: ([4.10](https://www.sec.gov/Archives/edgar/data/11544/000119312518095381/d542041dex42.htm))] | | | First Supplemental Indenture, dated as of March 26, 2018, between the Company and The Bank of New York Mellon, as Trustee, relating to $185,000,000 principal amount of the Company’s 5.700% Subordinated Debentures due 2058, including the form of the Securities as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on March 26, 2018). | | |

| [removed: [(4.11)](https://www.sec.gov/Archives/edgar/data/11544/000119312519315039/d797169dex42.htm)] [added: ([4.11](https://www.sec.gov/Archives/edgar/data/11544/000119312519315039/d797169dex42.htm))] | | | Second Supplemental Indenture, dated as of December 16, 2019, between the Company and the Bank of New York Mellon, as Trustee, relating to $300,000,000 principal amount of the Company's 5.100% Subordinated Debentures due 2059, including the form of the Securities as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company's Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on December 16, 2019). | | |

| [removed: ([4.12)](http://www.sec.gov/Archives/edgar/data/11544/000119312520249826/d70744dex42.htm)] [added: ([4.12](https://www.sec.gov/Archives/edgar/data/11544/000119312520249826/d70744dex42.htm))] | | | Third Supplemental Indenture, dated as of September 21, 2020, between the Company and The Bank of New York Mellon, as Trustee, relating to $250,000,000 principal amount of the Company’s 4.250% Subordinated Debentures due 2060, including the form of the Securities as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on September 21, 2020). | | |

| [removed: [(4.13)](https://www.sec.gov/Archives/edgar/data/11544/000119312521035890/d17400dex42.htm)] [added: ([4.13](https://www.sec.gov/Archives/edgar/data/11544/000119312521035890/d17400dex42.htm))] | | | Fourth Supplemental Indenture, dated as of February 10, 2021, between the Company and The Bank of New York Mellon, as Trustee, relating to $300,000,000 principal amount of the Company’s 4.125% Subordinated Debentures due 2061, including the form of the Securities as Exhibit A (incorporated by reference to Exhibit 4.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on February 10, 2021). | | |

| (4.14) | | | The instruments defining the rights of holders of the other long term debt securities of the Company are omitted pursuant to Section (b)(4)(iii)(A) of Item 601 of Regulation S-K. The Company agrees to furnish supplementally copies of these instruments to the [removed: Commission] [added: SEC] upon request. | | |

| [removed: [(10.1)](https://www.sec.gov/Archives/edgar/data/11544/000119312522095101/d335739dex101.htm)] [added: ([10.1](https://www.sec.gov/Archives/edgar/data/11544/000119312522095101/d335739dex101.htm))] | | | Credit Agreement, dated as of April 1, 2022, by and among W. R. Berkley Corporation, as borrower, each lender from time to time party thereto, Credit Suisse AG, New York Branch, JPMorgan Chase Bank, N.A. and Morgan Stanley Senior Funding, Inc. as Syndication Agents, and Bank of America, N.A., as Administrative Agent, Several L/C Agent and Fronting L/C Issuer (incorporated by reference to Exhibit 10.1 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on April 4, 2022). | | |

| [removed: ([10.](http://www.sec.gov/Archives/edgar/data/11544/000119312518122833/d560593ddef14a.htm)2)] [added: ([10.2](https://www.sec.gov/Archives/edgar/data/11544/000119312518122833/d560593ddef14a.htm))] | | | W. R. Berkley Corporation 2018 Stock Incentive Plan (incorporated by reference to Annex B of the Company’s 2018 Proxy Statement (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on April 19, 2018). | | |

| [removed: ([10.](http://www.sec.gov/Archives/edgar/data/11544/000095012303009001/y89010exv10w2.txt)3)] [added: ([10.3](https://www.sec.gov/Archives/edgar/data/11544/000095012303009001/y89010exv10w2.txt))] | | | Form of Restricted Stock Unit Agreement for grant of April 4, 2003 (incorporated by reference to Exhibit 10.2 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on August 6, 2003). | | |

| [removed: ([10.](http://www.sec.gov/Archives/edgar/data/11544/000095012305005491/y08534exv10w2.htm)4)] [added: ([10.4](https://www.sec.gov/Archives/edgar/data/11544/000095012305005491/y08534exv10w2.htm))] | | | Form of Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2003 Stock Incentive Plan (incorporated by reference to Exhibit 10.2 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on May 3, 2005). | | |

| [removed: ([10.](https://www.sec.gov/Archives/edgar/data/11544/000095012310073981/y85252exv10w1.htm)5)] [added: ([10.5](https://www.sec.gov/Archives/edgar/data/11544/000095012310073981/y85252exv10w1.htm))] | | | Form of Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2003 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on August 6, 2010). | | |

| [removed: ([10.](https://www.sec.gov/Archives/edgar/data/11544/000001154412000092/wrb9302012ex101.htm)6)] [added: ([10.6](https://www.sec.gov/Archives/edgar/data/11544/000001154412000092/wrb9302012ex101.htm))] | | | Form of Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2012 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company's Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 8, 2012). | | |

| [removed: ([10.](https://www.sec.gov/Archives/edgar/data/11544/000001154414000066/wrb9302014ex101.htm)7)] [added: ([10.7](https://www.sec.gov/Archives/edgar/data/11544/000001154414000066/wrb9302014ex101.htm))] | | | Form of 2014 Performance-Based Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2012 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company's Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 7, 2014). | | |

| [removed: ([10.](https://www.sec.gov/Archives/edgar/data/11544/000001154415000076/wrb9302015ex101.htm)8)] [added: ([10.8](https://www.sec.gov/Archives/edgar/data/11544/000001154415000076/wrb9302015ex101.htm))] | | | Form of 2015 Performance-Based Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2012 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company's Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 9, 2015). | | |

| [removed: ([10.](https://www.sec.gov/Archives/edgar/data/11544/000001154417000088/wrb9302017ex101.htm)9)] [added: ([10.9](https://www.sec.gov/Archives/edgar/data/11544/000001154417000088/wrb9302017ex101.htm))] | | | Form of 2017 Performance-Based Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2012 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 8, 2017). | | |

| [removed: ([10.](https://www.sec.gov/Archives/edgar/data/11544/000001154418000089/wrb930201810qex101.htm)10)] [added: ([10.10](https://www.sec.gov/Archives/edgar/data/11544/000001154418000089/wrb930201810qex101.htm))] | | | Form of 2018 Performance-Based Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2018 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 7, 2018). | | |

| [removed: ([10.1](http://www.sec.gov/Archives/edgar/data/11544/000001154420000143/wrb930202010-qex101.htm)1)] [added: ([10.11](https://www.sec.gov/Archives/edgar/data/11544/000001154420000143/wrb930202010-qex101.htm))] | | | Form of 2020 Performance-Based Restricted Stock Unit Agreement under the W. R. Berkley Corporation 2018 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company’s Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 5, 2020). | | |

| [removed: [(10.12)](https://www.sec.gov/Archives/edgar/data/11544/000001154424000005/wrb1231202310-kex1012.htm)] [added: ([10.12](https://www.sec.gov/Archives/edgar/data/11544/000001154424000005/wrb1231202310-kex1012.htm))] | | | Form of 2023 Performance-Based Restricted Stock Unit Agreement Under the W. R. Berkley Corporation 2018 Stock Incentive Plan (incorporated by reference to Exhibit 10.12 of the Company's Annual Report on Form 10-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on February 23, 2024). | | |

| [removed: [(10.13)](https://www.sec.gov/Archives/edgar/data/11544/000001154424000028/wrb930202410-qex101.htm)] [added: ([10.13](https://www.sec.gov/Archives/edgar/data/11544/000001154424000028/wrb930202410-qex101.htm))] | | | Form of 2024 Performance-Based Restricted Stock Unit Agreement Under the W. R. Berkley Corporation 2018 Stock Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company's Quarterly Report on Form 10-Q (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 4, 2024). | | |

| ([10.14](https://www.sec.gov/Archives/edgar/data/11544/000089914021000723/w47655837b.htm)) | | | W. R. Berkley Corporation Deferred Compensation Plan for Officers as amended and restated effective December 1, 2021 (incorporated by reference to Exhibit 10.1 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 12, 2021). | | |

| [removed: [(10.15)](https://www.sec.gov/Archives/edgar/data/11544/000089914021000723/w47655837c.htm)] [added: ([10.15](https://www.sec.gov/Archives/edgar/data/11544/000089914021000723/w47655837c.htm))] | | | W. R. Berkley Corporation Deferred Compensation Plan for Directors as amended and restated effective December 1, 2021 (incorporated by reference to Exhibit 10.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the [removed: Commission] [added: SEC] on November 12, 2021). | | |

| ([3.6](https://www.sec.gov/Archives/edgar/data/11544/000001154425000013/exhibit316132025.htm)) | | | Amendment, dated June 11, 2025, to the Company’s Restated Certificate of Incorporation, as amended (incorporated by reference to Exhibit 3.1 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the SEC on June 13, 2025). | | |

| ([4.1](https://www.sec.gov/Archives/edgar/data/11544/000001154426000005/wrb1231202510-kex41.htm)) | | | Description of Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934. | | |

| ([10.22](https://www.sec.gov/Archives/edgar/data/11544/000001154425000009/wrb331202510-qex101.htm)) | | | Form of 2025 Performance Unit Award Agreement under the W. R. Berkley Corporation 2019 Long-Term Incentive Plan (incorporated by reference to Exhibit 10.1 of the Company's Quarterly Report on Form 10-Q (File No. 1-15202) filed with the SEC on May 2, 2025). | | |

| ([10.25](https://www.sec.gov/Archives/edgar/data/11544/000119312525066218/d934374dex101.htm)) | | | Framework Agreement, dated as of March 28, 2025, by and between WR Berkley & Others LLC and Mitsui Sumitomo Insurance Company, Limited (including the form of Amended and Restated Limited Liability Company Agreement attached as Exhibit A) (incorporated by reference to Exhibit 10.1 of the Company's Current Report on Form 8-K (File No. 1-15202) filed with the SEC on March 28, 2025).* | | |

| ([10.26](https://www.sec.gov/Archives/edgar/data/11544/000119312525066218/d934374dex102.htm)) | | | Letter Agreement, dated as of March 28, 2025, by and between W. R. Berkley Corporation and Mitsui Sumitomo Insurance Company, Limited (incorporated by reference to Exhibit 10.2 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the SEC on March 28, 2025).* | | |

| ([10.27](https://www.sec.gov/Archives/edgar/data/11544/000119312525066218/d934374dex103.htm)) | | | Confidentiality Agreement, dated as of March 28, 2025, by and between W. R. Berkley Corporation and Mitsui Sumitomo Insurance Company, Limited (incorporated by reference to Exhibit 10.3 of the Company’s Current Report on Form 8-K (File No. 1-15202) filed with the SEC on March 28, 2025). | | |

| | | | | | |

| | | | | | |

| | | | | | |

| | | | | | |

| | | | | | |

| (101) | | | The following financial statements from the Company's Annual Report on Form 10-K for the year ended December 31, 2025, formatted in Inline XBRL: (i) Consolidated Statements of Income, (ii) Consolidated Statements of Comprehensive Income, (iii) Consolidated Balance Sheets, (iv) Consolidated Statements of Stockholders' Equity, (v) Consolidated Statements of Cash Flows and (vi) Notes to Consolidated Financial Statements. | | |

| (104) | | | Cover Page Interactive Data File (embedded within the Inline XBRL document). | | |

| * | | | Schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K. The Company hereby undertakes to furnish supplemental copies of any of the omitted schedules upon request by the SEC. | | |

| ([19.1](https://www.sec.gov/Archives/edgar/data/11544/000001154425000005/wrb12312024ex191insidertra.htm)) | | | Insider Trading Policy | | |

| /s/ William R. Berkley | | | | | | Executive Chairman | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ W. Robert Berkley, Jr. | | | | | | President | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ Christopher L. Augostini | | | | | | Director | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ Ronald E. Blaylock | | | | | | Director | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ Mary C. Farrell | | | | | | Director | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ María Luisa Ferré | | | | | | Director | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ Marie A. Mattson | | | | | | Director | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ Daniel L. Mosley | | | | | | Director | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ Jonathan Talisman | | | | | | Director | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| /s/ Richard M. Baio | | | | | | Executive Vice President | | | | | | February [removed: 24, 2025] [added: 27, 2026] | | |

| (In thousands) | | | [added: 2025 | | | | | |] 2024 | | | | | | 2023 | | |

| Cash and cash equivalents [added: at end of year] | | | $ | [added: 55,322 | | | | | $ |] 112,931 | | | | | $ | 128,434 | |

| Fixed maturity securities available for sale at fair value (cost [removed: $251,938] [added: $641,917] and [removed: $190,708] [added: $251,938] at December 31, [removed: 2024] [added: 2025] and [removed: 2023, respectively)] [added: 2024)] | | | [removed: 251,800] [added: 642,451] | | | | | | [removed: 189,189] [added: 251,800] | | |

| Loans receivable (net of allowance for expected credit losses of [removed: $591] [added: $161] and [removed: $1,146] [added: $591] at December 31, [removed: 2024] [added: 2025] and [removed: 2023, respectively)] [added: 2024)] | | | [removed: 27,659] [added: 23,089] | | | | | | [removed: 91,304] [added: 27,659] | | |

| Equity securities, at fair value (cost $3,430 at both December 31, [removed: 2024] [added: 2025] and [removed: 2023)] [added: 2024)] | | | 3,430 | | | | | | 3,430 | | |

| Investment in subsidiaries | | | [removed: 10,770,734] [added: 11,940,355] | | | | | | [removed: 9,887,117] [added: 10,770,734] | | |

| Current federal income taxes | | | [removed: 36,417] [added: —] | | | | | | [removed: —] [added: 36,417] | | |

| Deferred federal income taxes | | | [removed: 228,329] [added: 151,031] | | | | | | [removed: 278,946] [added: 228,329] | | |

| Property, furniture and equipment at cost, less accumulated depreciation | | | [removed: 9,320] [added: 8,581] | | | | | | [removed: 10,382] [added: 9,320] | | |

| Other assets | | | [removed: 126,799] [added: 62,179] | | | | | | [removed: 44,186] [added: 126,799] | | |

| Total assets | | | $ | [removed: 11,567,419] [added: 12,886,438] | | | | | $ | [removed: 10,632,988] [added: 11,567,419] | |

| Due to subsidiaries | | | $ | [removed: 182,445] [added: 144,740] | | | | | $ | [removed: 178,676] [added: 182,445] | |

| Other liabilities | | | [removed: 158,281] [added: 188,851] | | | | | | [removed: 166,399] [added: 158,281] | | |

| Current federal income taxes | | | [removed: —] [added: 19,626] | | | | | | [removed: 1,721] [added: —] | | |

| Subordinated debentures | | | [removed: 1,009,808] [added: 1,010,527] | | | | | | [removed: 1,009,090] [added: 1,009,808] | | |

| Senior notes | | | [removed: 1,821,774] [added: 1,821,876] | | | | | | [removed: 1,821,671] [added: 1,821,774] | | |

| Total liabilities | | | [removed: 3,172,308] [added: 3,185,620] | | | | | | [removed: 3,177,557] [added: 3,172,308] | | |

| Additional paid-in capital | | | [removed: 984,825] [added: 987,708] | | | | | | [removed: 964,789] [added: 984,825] | | |

| Retained earnings (including accumulated undistributed net income of subsidiaries of [removed: $9,216,210] [added: $9,674,616] and [removed: $8,497,674] [added: $9,216,210] at December 31, [removed: 2024] [added: 2025] and [removed: 2023,] [added: 2024,] respectively) | | | [removed: 12,265,070] [added: 13,344,204] | | | | | | [removed: 11,040,908] [added: 12,265,070] | | |