Note 13. Cash and Marketable Securities

Cash, money market funds and certificates of deposits with maturities of three months or less when purchased are included in Cash and cash equivalents on the accompanying condensed consolidated statements of financial position. As of June 30, 2025 and December 31, 2024, the amortized cost of our short- and long-term investments was less than $1 million and $53 million, respectively, and the estimated fair value of these investments was less than $1 million and $53 million, respectively. As of June 30, 2025, short- and long-term marketable securities primarily consisted of certificates of deposit. There were no unrealized losses which had been in a loss position for more than one year as of June 30, 2025.

Gains and losses on sales of investments, as determined on a specific identification basis, are included in investment income in the period they are realized. We periodically review our portfolio of investments to determine whether there has been an other-than-temporary decline in the value of the investments from factors such as deterioration in the financial condition of the issuer or the market(s) in which the issuer competes. During the three months ended June 30, 2025, there were less than $1 million each in proceeds from sales of securities, maturities, gross realized gains and gross realized losses resulting from sales of available-for-sale securities. During the six months ended June 30, 2025, there were $48 million in proceeds from sales of securities, $12 million in maturities and less than $1 million each in gross realized gains and gross realized losses resulting from sales of available-for-sale securities. During the three months and six months ended June 30, 2024, there were no proceeds, maturities, gross realized gains and gross realized losses resulting from sales of available-for-sale securities. There were no impairment charges due to other-than-temporary declines in the value of certain investments for the six months ended June 30, 2025 and 2024.