Item 1A. Risk Factors

There have been no material changes to the risk factors disclosed in Item 1A in our 2024 10-K, except as follows:

The Merger may not be completed in a timely manner or at all, and the Merger Agreement may be terminated in accordance with its terms.

The Merger is subject to a number of conditions that must be satisfied or waived prior to the completion of the Merger, including, among others, the receipt of requisite regulatory approvals and the approval for listing on the New York Stock Exchange, or NYSE, of the shares of our common stock issuable to IPG stockholders pursuant to the Merger Agreement.

These conditions to the completion of the Merger may not be satisfied or waived in a timely manner or at all, and, accordingly, the Merger may be delayed or may not be completed. For example, Omnicom or IPG may be unable to obtain governmental and regulatory approvals required for the Merger, or such approvals may be received later than anticipated or may result in the imposition of conditions that could adversely affect the combined company or the expected benefits of the Merger.

If the Merger is not completed by December 8, 2025, which date may be extended to June 8, 2026 in certain circumstances, either we or IPG may choose not to proceed with the Merger by terminating the Merger Agreement, and the parties can mutually decide to terminate the Merger Agreement at any time. In addition, we and IPG may elect to terminate the Merger in certain other circumstances as set forth in the Merger Agreement. If the Merger Agreement is terminated under specified circumstances, Omnicom would be required to pay IPG a termination fee of $676 million.

Litigation relating to the Merger, if any, could result in an injunction preventing the completion of the Merger and/or substantial costs to us.

Following the announcement of the Merger, several lawsuits have been filed by purported shareholders of Omnicom and IPG concerning the Merger. Omnicom and IPG have also received demand letters from counsel representing purported individual shareholders of Omnicom and IPG, respectively, alleging, among other things, that the joint proxy statement/prospectus filed by Omnicom and IPG in connection with the Merger contains disclosure deficiencies and/or incomplete information regarding the Merger.

Securities class action lawsuits and derivative lawsuits are often brought against public companies that have entered into acquisition, merger or other business combination agreements like the Merger Agreement. Even if such a lawsuit is without merit, defending against these claims can result in substantial costs and divert management time and resources. An adverse judgment could result in monetary damages, which could have a negative impact on our liquidity and financial condition. Lawsuits that have been, or may in the future, be brought against us, IPG, or our or their directors could also seek, among other things, injunctive relief or other equitable relief, including a request to rescind parts of the Merger Agreement already implemented and to otherwise enjoin the parties from consummating the Merger. One of the conditions to the closing of the Merger is that no Law or Order (each as defined in the Merger Agreement) is promulgated, entered, enforced, enacted or issued by any governmental entity of competent jurisdiction in which we, IPG, or our or their subsidiaries have material assets or material business operations, which prohibits, restrains or makes illegal the consummation of the Merger. Consequently, if a plaintiff is successful in obtaining an injunction prohibiting completion of the Merger, that injunction may delay or prevent the Merger from being completed within the expected timeframe or at all, which may adversely affect our businesses, results of operations, financial condition and cash flows. In addition, either we or IPG may terminate the Merger Agreement if any Law or Order has been promulgated, entered, enforced, enacted or issued by any governmental entity of competent jurisdiction in which we, IPG, or our or their subsidiaries have material assets or material business operations, which is in effect and permanently prohibits, restrains, enjoins or makes illegal the consummation of the Merger, so long as our or Merger Sub’s (in the case of a termination by us) or IPG’s (in the case of a termination by IPG) material breach of any obligations under the Merger Agreement has not been the primary cause of, or resulted in, the enactment or issuance of such Law or Order, decree, ruling, injunction or other action.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

Common stock repurchases during the three months ended March 31, 2025:

During the three months ended March 31, 2025, we purchased 989,825 shares of our common stock in the open market for general corporate purposes under a plan meeting the requirements of Rule 10b5-1 under the Exchange Act, and we withheld 11,945 shares from employees to satisfy estimated statutory income tax obligations related to vesting of restricted stock awards and stock

option exercises. The value of the common stock withheld was based on the closing price of our common stock on the applicable vesting or exercise date. There were no unregistered sales of equity securities during the three months ended March 31, 2025.