The Company’s investment strategy is focused on capital preservation. The Company invests in instruments that meet the credit quality standards outlined in the Company’s investment policy. This policy also limits the amount of credit exposure to any one issue or type of instrument. As of each of September 30, 2023 and December 31, 2022, the Company’s investments were in government money market funds, certificates of deposit, commercial paper, corporate debt securities and government debt securities. There were no sales of available-for-sale securities during the three and nine months ended September 30, 2023 or during the year ended December 31, 2022.


As of September 30, 2023	Amortized Cost		Gross Unrealized Gains (1)		Gross Unrealized Losses (1)			Aggregate Estimated Fair Value
Commercial paper (2)	$	90,828	$	1	$	(1	)	$	90,828
Corporate debt securities (2)		98,539		26		(226	)		98,339
Government debt securities (2)		150,228		1		(340	)		149,889
	$	339,595	$	28	$	(567	)	$	339,056

(1)

Unrealized gains and losses on available-for-sale securities are included as a component of comprehensive loss. At September 30, 2023, there were 10 securities in an unrealized gain position and there were 97 securities in an unrealized loss position. The unrealized gains were less than $19,000 individually and $29,000 in the aggregate. The unrealized losses were less than $48,000 individually and $567,000 in the aggregate. The Company does not intend to sell these investments and it is not more likely than not that the Company will be required to sell these investments before recovery of their amortized cost basis, which may be at maturity. The Company reviews its investments to identify and evaluate investments that have an indication of possible other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value.

Investments classified as available-for-sale as of December 31, 2022 consisted of the following (in thousands):


As of December 31, 2022	Amortized Cost		Gross Unrealized Gains (1)		Gross Unrealized Losses (1)			Aggregate Estimated Fair Value
Commercial paper (2)	$	43,780	$	—	$	—		$	43,780
Corporate debt securities (2)		72,183		—		(824	)		71,359
Government debt securities (2)		3,732		—		(18	)		3,714
	$	119,695	$	—	$	(842	)	$	118,853

(1)

Unrealized gains and losses on available-for-sale securities are included as a component of comprehensive loss. At December 31, 2022, there were no securities in an unrealized gain position and 39 securities in an unrealized loss position. The unrealized losses were less than $124,000 individually and $842,000 in the aggregate. 22 of these securities have been in a continuous unrealized loss or unrealized gain position for more than 12 months. The Company does not intend to sell these investments and it is not more likely than not that the Company will be required to sell these investments before recovery of their amortized cost basis, which may be at maturity. The Company reviews its investments to identify and evaluate investments that have an indication of possible other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value.