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Short-Term Investments | 12 Months Ended
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Dec. 31, 2023
Short-Term Investments |
Short-Term Investments | 4. Short-Term Investments ​ The following tables summarize the short-term investments held at December 31, 2023 and 2022 (in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | Gross Unrealized | ​ | Gross Unrealized | ​ | ​ | ​
​ |  | Amortized Cost |  | Gains |  | Losses |  | Fair Value
December 31, 2023 | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Reverse repurchase agreements | ​ | $ | 71,000 | ​ | $ | — | ​ | $ | — | ​ | $ | 71,000
Total | ​ | $ | 71,000 | ​ | $ | — | ​ | $ | — | ​ | $ | 71,000
​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Gross Unrealized | ​ | Gross Unrealized | ​ | ​ | ​
​ |  | Amortized Cost |  | Gains |  | Losses |  | Fair Value
December 31, 2022 | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Corporate debt securities | ​ | $ | 16,508 | ​ | $ | — | ​ | $ | (63) | ​ | $ | 16,445
Treasury bills | ​ | ​ | 5,983 | ​ | ​ | — | ​ | ​ | (3) | ​ | ​ | 5,980
Yankee securities | ​ | ​ | 2,000 | ​ | ​ | — | ​ | ​ | (1) | ​ | ​ | 1,999
U.S. agency bonds | ​ | ​ | 3,000 | ​ | ​ | — | ​ | ​ | (12) | ​ | ​ | 2,988
Reverse repurchase agreements | ​ | ​ | 178,500 | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 178,500
Total | ​ | $ | 205,991 | ​ | $ | — | ​ | $ | (79) | ​ | $ | 205,912
​ The contractual maturities of all short-term investments held at December 31, 2023 and December 31, 2022 were one year or less. There were no short-term investments in an unrealized loss position at December 31, 2023. There were 16 short-term investments in an unrealized loss position at December 31, 2022 with an aggregate value of $25.6 million. These investments were in a loss position for less than 12 months and the Company considered the loss to be temporary in nature. The Company considered the decline in market value for these securities to be primarily attributable to economic and market conditions. ​ Gross realized gains and losses on the sales of short-term investments are included in other income, net. Unrealized holding gains or losses for the period that have been included in accumulated other comprehensive income, as well as gains and losses reclassified out of accumulated other comprehensive income into other income, net, were not material to the Company’s consolidated results of operations. The cost of investments sold or the amount reclassified out of the accumulated other comprehensive income into other income, net is based on the specific identification method for purposes of recording realized gains and losses. All proceeds in the years ended December 31, 2023 and 2022 related to maturities of underlying investments. The gains on proceeds from maturities of short-term investments were not material to the Company’s consolidated results of operations for the years ended December 31, 2023 and 2022.

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