The Company's investments are classified as available-for-sale. The following table summarizes the amortized cost, gross unrealized gains and losses, and fair value of available-for-sale investments as of June 30, 2023:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
U.S. government debt securities	$	73,047	$	15	$	(276)	$	72,786
U.S. agency securities	991		8		(13)		986
Certificates of deposit	5,247		—		(4)		5,243
Total	$	79,285	$	23	$	(293)	$	79,015

The following table summarizes the amortized cost, gross unrealized gains and losses, and fair value of available-for-sale investments as of December 31, 2022:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
U.S. government debt securities	$	51,755	$	—	$	(760)	$	50,995
Certificates of deposit	97		—		—		97
Total	$	51,852	$	—	$	(760)	$	51,092

The estimated fair value of available-for-sale investments classified by their contractual maturities as of June 30, 2023 was:


Due within one year	$	71,888
After one year through two years	7,127
Total	$	79,015

Changes in market interest rates and bond yields cause certain investments to fall below their cost basis, resulting in unrealized losses on investments. We do not intend to sell these investments nor is it more likely than not that the Company will be required to sell these investments, prior to maturity or recovery of amortized cost.