Marketable securities consisted of the following as of March 31, 2024 (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. treasury securities	$	149,992	$	7	$	(64)	$	149,935
Commercial paper	33,343		—		(37)		33,306
Corporate notes and obligations	133,840		9		(127)		133,722
Total marketable securities	$	317,175	$	16	$	(228)	$	316,963

Marketable securities consisted of the following as of December 31, 2023 (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. treasury securities	$	128,479	$	124	$	(27)	$	128,576
Commercial paper	47,415		1		(35)		47,381
Corporate notes and obligations	139,747		61		(128)		139,680
Time deposits	4,525		—		(1)		4,524
Total marketable securities	$	320,166	$	186	$	(191)	$	320,161

All marketable securities held as of March 31, 2024 and December 31, 2023 had a contractual maturity of less than one year. During the three months ended March 31, 2024 and 2023, there were maturities of marketable securities of $107.3 million and $103.9 million, respectively. There were no sales, realized losses, or impairments of marketable securities during the three months ended March 31, 2024 or 2023.

Strategic investment activity during the three months ended March 31, 2024 is summarized as follows (in thousands):


	Equity Securities		Limited Partnerships		Available-for- Sale Debt Securities		Total
Balance as of December 31, 2023	$	7,179	$	3,986	$	362	$	11,527
Interest accrued on available-for-sale debt securities	—		—		2		2
Purchases of strategic investments	—		210		—		210
Unrealized gain on strategic investments	671		88		—		759
Balance as of March 31, 2024	$	7,850	$	4,284	$	364	$	12,498

Strategic investment activity during the three months ended March 31, 2023 is summarized as follows (in thousands):


	Equity Securities		Limited Partnerships		Available-for- Sale Debt Securities		Total
Balance as of December 31, 2022	$	7,286	$	3,402	$	355	$	11,043
Interest accrued on available-for-sale debt securities	—		—		2		2
Purchases of strategic investments	—		149		—		149
Unrealized (loss) gain on strategic investments	(1)		37		—		36
Balance as of March 31, 2023	$	7,285	$	3,588	$	357	$	11,230

Strategic investments are recorded in other assets on the accompanying condensed consolidated balance sheets. As of March 31, 2024, in connection with the Company’s investments in limited partnerships, it has a contractual obligation to provide additional investment funding of up to $5.4 million at the option of the investees. No impairment losses were recorded in any period presented.