Item 3. Quantitative and Qualitative Disclosures about Market Risk

Our earnings and financial position are exposed to financial market risk, including those resulting from changes in interest rates.

Interest rate risk also represents a market risk factor affecting our consolidated financial position due to our significant investment portfolio, consisting primarily of fixed maturity securities of investment-grade quality with a weighted average S&P credit rating of AA- at September 30, 2021. Our net unrealized position decreased $326 million from a net unrealized gain position of $514 million at December 31, 2020 to a net unrealized gain position of $188 million at September 30, 2021. At September 30, 2021, we had gross unrealized losses of $113 million on our investment portfolio primarily due to an increase in market interest rates since the time the securities were purchased. There were no material credit allowances during the nine months ended September 30, 2021. While we believe that these securities in an unrealized loss will recover in value over time and we currently do not have the intent to sell such securities, given the current market conditions and the significant judgments involved, there is a continuing risk that future declines in fair value may occur and material realized losses from sales or credit allowances may be recorded in future periods.

Duration is the time-weighted average of the present value of the bond portfolio’s cash flow. Duration is indicative of the relationship between changes in fair value and changes in interest rates, providing a general indication of the sensitivity of the fair values of our fixed maturity securities to changes in interest rates. However, actual fair values may differ significantly from estimates based on duration. The average duration of our investment portfolio, including cash and cash equivalents, was approximately 3.5 years as of September 30, 2021 and approximately 3.0 years as of December 31, 2020. The increase in the average duration is reflective of various portfolio management activities and the decreased holdings of cash and cash equivalents. Based on the duration, including cash equivalents, a 1% increase in interest rates would generally decrease the fair value of our securities by approximately $632 million at September 30, 2021.