(4) Investments

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All investments in fixed income securities are classified as cash equivalents or available-for-sale in the condensed consolidated balance sheets based on the underlying maturity date of each investment. Fixed income securities are recorded at their estimated fair value. The amortized cost, gross unrealized holding gains and losses included in accumulated other comprehensive income and the fair value of the fixed income securities as of March 31, 2026 and December 31, 2025 are presented in the tables below (in thousands):

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The Company invests in highly rated investment grade debt securities. As of March 31, 2026, all of the Company’s available-for-sale securities have final maturities of one year or less, except for five U.S. treasury securities classified as long-term with final maturities extending through August 15, 2027. The Company reviews the individual securities that have unrealized losses on a regular basis. The Company evaluates whether it has the intention to sell any of these investments and whether it is more likely than not that it will be required to sell any of them before recovery of the amortized cost basis. The Company additionally evaluates whether the decline in fair value of the securities below their amortized cost basis is related to credit losses or other factors.

As of March 31, 2026, there were eight securities with an aggregate market value of $235.0 million in an unrealized loss position. The unrealized losses related to these securities aggregated to $0.5 million. None of the securities had been in an unrealized loss position for more than one year. The Company determined that it would not need to sell any of the securities prior to recovery of their amortized cost basis. The Company also determined that the unrealized losses for its available-for-sale securities as of March 31, 2026 were attributable to changes in interest rates and other non-credit related factors. Accordingly, the Company determined that none of the unrealized losses were other-than-temporary, and that recognition of an impairment charge was not required as of March 31, 2026. None of the Company’s available-for-sale securities were in an unrealized loss position as of December 31, 2025. No available-for-sale securities were sold during the three months ended March 31, 2026 or March 31, 2025.

See Note 5 for additional information regarding the fair value of the Company’s investments.