Investments

6 Months Ended

Jun. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Marketable securities

Marketable securities consisted of the following as of June 30, 2024 (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. treasury securities	$	167,659	$	3	$	(96)	$	167,566
Commercial paper	53,138		—		(68)		53,070
Corporate notes and obligations	204,137		11		(234)		203,914
Total marketable securities	$	424,934	$	14	$	(398)	$	424,550

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

The following table summarizes the estimated fair value of investments classified as marketable securities by contractual maturity date (in thousands):


	June 30, 2024		December 31, 2023
Due within 1 year	$	379,120	$	320,161
Due in 1 to 2 years	45,430		—
Total marketable securities	$	424,550	$	320,161

During the six months ended June 30, 2024 and 2023, there were maturities of marketable securities of $226.1 million and $222.7 million, respectively. During the six months ended June 30, 2023, there were sales of marketable securities of $5.5 million. There were no sales of marketable securities during the six months ended June 30, 2024. Realized losses on sales of marketable securities are recorded in other expense, net on the condensed consolidated statements of operations and comprehensive loss. Such losses were immaterial during the six months ended June 30, 2023. There were no impairments of marketable securities during the six months ended June 30, 2024 or 2023.

Strategic investments

Strategic investment activity during the six months ended June 30, 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	—		—		4		4
Purchases of strategic investments	498		574		—		1,072
Unrealized gain on strategic investments	671		154		—		825
Impairment of strategic investments	(184)		—		—		(184)
Balance as of June 30, 2024	$	8,164	$	4,714	$	366	$	13,244

Strategic investment activity during the six months ended June 30, 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	—		—		4		4
Purchases of strategic investments	—		442		—		442
Unrealized loss on strategic investments	—		(6)		—		(6)
Balance as of June 30, 2023	$	7,286	$	3,838	$	359	$	11,483

Strategic investments are recorded in other assets on the accompanying condensed consolidated balance sheets. As of June 30, 2024, in connection with the Company’s investments in limited partnerships, it has a contractual obligation to provide additional investment funding of up to $5.1 million at the option of the investees.