Fair Value Measurements

6 Months Ended

Jun. 30, 2024

Fair Value Disclosures [Abstract]

Fair Value Measurements

5. Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset in an orderly transaction between market participants at the measurement date. To increase the comparability of fair value measures, the following hierarchy prioritizes the inputs to valuation methodologies used to measure fair value:

•Level 1: Quoted market prices in active markets for identical assets or liabilities

•Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data

•Level 3: Unobservable inputs reflecting the reporting entity’s own assumptions or external inputs from inactive markets

We classify our cash equivalents and marketable securities within Level 1 or Level 2 because we use quoted market prices or alternative pricing sources and models utilizing market observable inputs to determine their fair value. There were no transfers between levels during the periods presented.

The following table sets forth our financial assets that are measured at fair value on a recurring basis:

		June 30, 2024
	Fair value hierarchy level	Cost or amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
		(in thousands)
Cash equivalents:
Money market funds	Level 1	$	352,687	$	—	$	—	$	352,687
Commercial paper	Level 2	33,887		—		(15)		33,872
Marketable securities:
U.S. treasury securities	Level 1	794,614		100		(549)		794,165
U.S. agency bonds	Level 2	89,983		—		(191)		89,792
Non-U.S. government securities	Level 2	4,938		—		(3)		4,935
Corporate bonds	Level 2	135,236		56		(244)		135,048
Commercial paper	Level 2	207,299		2		(142)		207,159
Total		$	1,618,644	$	158	$	(1,144)	$	1,617,658

		December 31, 2023
	Fair value hierarchy level	Cost or amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
		(in thousands)
Cash equivalents:
Money market funds	Level 1	$	345,555	$	—	$	—	$	345,555
Commercial paper	Level 2	9,994		—		(9)		9,985
Marketable securities:
U.S. treasury securities	Level 1	426,734		697		(188)		427,243
U.S. agency bonds	Level 2	77,535		13		(34)		77,514
Non-U.S. government securities	Level 2	21,723		10		(27)		21,706
Corporate bonds	Level 2	94,725		310		(81)		94,954
Certificates of deposit	Level 2	2,810		—		(1)		2,809
Commercial paper	Level 2	187,596		148		(24)		187,720
Total		$	1,166,672	$	1,178	$	(364)	$	1,167,486

Gross unrealized gains (losses) within accumulated other comprehensive income (loss) were immaterial as of June 30, 2024 and December 31, 2023. There were no impairment charges due to credit losses during the three and six months ended June 30, 2024 and 2023.

As of June 30, 2024, the amortized cost of marketable securities with maturities less than one year was $977.3 million. The amortized cost of marketable securities with maturities between one and five years was $254.8 million.