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, 2024:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
U.S. government debt securities	$	8,359	$	15	$	(31)	$	8,343

Certificates of deposit	1,848		—		—		1,848

Total	$	10,207	$	15	$	(31)	$	10,191

In addition, at June 30, 2024 and December 31, 2023, the Company held a U.S. government debt security valued at $5,864 and $1,502, respectively, which was included in cash and cash equivalents in the condensed consolidated balance sheet as this investment had an original maturity of less than three months when purchased.

The estimated fair value of available-for-sale investments was $10,191 as of June 30, 2024, and these available-for-sale investments all contractually mature within one year.

The following table summarizes the amortized cost, gross unrealized gains and losses, and fair value of available-for-sale investments as of December 31, 2023:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Aggregate Fair Value
U.S. government debt securities	$	51,704	$	102	$	(135)	$	51,671
Certificates of deposit	3,361		1		(1)		3,361
Corporate bonds	245		—		—		245
Total	$	55,310	$	103	$	(136)	$	55,277

Changes in market interest rates and bond yields cause certain investments to fall below their cost basis, resulting in unrealized losses on investments. The Company does 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.