Marketable Securities and Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2021

Marketable Securities and Fair Value Measurements [Abstract]

Summary of marketable securities

The following tables present our marketable securities by security type:

	As of June 30, 2021
			Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair
(in thousands)	Cost		Gains		Losses		Value
U.S. treasury securities	$	33,117	$	4	$	—	$	33,121

	As of December 31, 2020
			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
(in thousands)	Cost		Gains		Losses		Value
U.S. treasury securities	$	129,446	$	9	$	(4)	$	129,451
Commercial paper		52,441		—		—		52,441
Corporate debt securities		17,542		4		—		17,546
Total	$	199,429	$	13	$	(4)	$	199,438

Summary of assets measured at fair value on a recurring basis

The following tables present our assets that are measured at fair value on a recurring basis and indicate the level within the fair value hierarchy of the valuation techniques that we utilized to determine such fair value:

	Fair Value Measurements at June 30, 2021 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	226,378	$	—	$	—	$	226,378
Marketable securities:
U.S. treasury securities		—		33,121		—		33,121

	Fair Value Measurements at December 31, 2020 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	63,827	$	—	$	—	$	63,827
Marketable securities:
U.S. treasury securities		—		129,451		—		129,451
Commercial paper		—		52,441		—		52,441
Corporate debt securities		—		17,546		—		17,546
Total	$	63,827	$	199,438	$	—	$	263,265