The following table summarizes the Company’s marketable securities as of September 30, 2020 (in thousands):

	Amortized Cost Basis		Unrealized Gains		Unrealized Losses		Fair Value
Marketable securities:
US government	$	42,204	$	347	$	—	$	42,551
Corporate bonds		36,939		141		—		37,080
Commercial paper		19,692		4		—		19,696
Money market funds⁽¹⁾		3,288		—		—		3,288
Certificates of deposit		1,631		—		—		1,631
	$	103,754	$	492	$	—	$	104,246

The Company classifies its marketable securities as available-for-sale and they consist of all debt securities. The amortized cost basis as of September 30, 2020 includes $0.3 million of accrued interest receivable. As of September 30, 2020, marketable securities were in a net unrealized gain position of $0.5 million. Unrealized gains and losses on available-for-sale debt securities are included as a component of comprehensive loss.

As of September 30, 2020, the Company did not hold any marketable securities in an unrealized loss position. Per the Company’s general investment strategy, the Company does not intend to sell the investments before maturity. As of September 30, 2020, the Company believes the cost basis for its marketable securities were recoverable in all material aspects and no credit impairments were recognized in the period.

The Company’s marketable securities as of September 30, 2020 mature at various dates through February 2022. The fair values of marketable securities by contractual maturity consist of the following (in thousands):

	September 30, 2020		December 31, 2019
Maturities within one year	$	98,346	$	114,386
Maturities after one year through three years		5,900		48,556
	$	104,246	$	162,942