The following tables summarize the amortized cost and estimated fair value of the Company's available-for-sale investments as of December 31, 2024 and 2023 (in thousands):


	December 31, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Short-term investments:
U.S. Treasury securities	$	129,294	$	436	$	—	$	129,730
U.S. government-sponsored enterprise securities		9,926		6		—		9,932
Long-term investments:
U.S. Treasury securities		5,084		5		—		5,089
	$	144,304	$	447	$	—	$	144,751


	December 31, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Short-term investments:
U.S. Treasury securities	$	41,470	$	22	$	(19	)	$	41,473
U.S. government-sponsored enterprise securities		50,056		—		(86	)		49,970
	$	91,526	$	22	$	(105	)	$	91,443

Certain short-term debt securities with original maturities of less than 90 days are included in cash and cash equivalents on the consolidated balance sheets and are not included in the tables above. As of December 31, 2024 and 2023, all short-term investments had contractual maturities within one year. As of December 31, 2024, all long-term investments had contractual maturities between one to two years.

There were no available-for-sale securities held by the Company in an unrealized loss position as of December 31, 2024. As such, the Company does not consider these investments to be impaired and there are no allowances for credit losses as of December 31, 2024.