The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:

Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3—Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value.

As of March 31, 2021, financial assets measured and recognized at fair value are as follows (in thousands):

		March 31, 2021
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Assets
U.S. government securities	Level 1	$	35,020	$	13	$	—		$	35,033
Corporate bonds	Level 2		76,468		5		(18	)		76,455
Commercial paper	Level 2		62,161		—		—			62,161
Marketable securities			173,649		18		(18	)		173,649
Money market funds⁽¹⁾	Level 1		136,477		—		—			136,477
Total fair value of assets		$	310,126	$	18	$	(18	)	$	310,126

(1)	Included in cash and cash equivalents on the balance sheet

As of December 31, 2020, financial assets measured and recognized at fair value are as follows (in thousands):

		December 31, 2020
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Assets
U.S. government securities	Level 1	$	80,020	$	10	$ —			$	80,030
Corporate bonds	Level 2		72,573		11		(14	)		72,570
Commercial paper	Level 2		63,948	—		—				63,948
Marketable securities			216,541		21		(14	)		216,548
Money market funds⁽¹⁾	Level 1		67,065		—		—			67,065
Total fair value of assets		$	283,606	$	21	$	(14	)	$	283,613

(1)	Included in cash and cash equivalents on the balance sheet

As of March 31, 2021, all marketable securities had a remaining maturity of one year or less, except for corporate bonds with a fair value of $8.1 million that had maturities of one to two years. As of December 31, 2020, all marketable securities had a remaining maturity of one year or less. There were no financial liabilities measured and recognized at fair value as of March 31, 2021 and December 31, 2020.