Investments

9 Months Ended

Sep. 30, 2023

2. Investments

Investments consists of available-for-sale securities as follows (in thousands):


	September 30, 2023
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Short-term marketable securities:
U.S. Treasury securities	$	31,746	$	—	$	(9	)	$	31,737
Commercial paper		3,222		—		—			3,222
Corporate bonds		2,000		—		—			2,000
U.S. government agency debt securities		13,123		—		(2	)		13,121
Total short-term marketable securities	$	50,091	$	—	$	(11	)	$	50,080


	December 31, 2022
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Short-term marketable securities:
U.S. Treasury securities	$	30,628	$	—	$	(177	)	$	30,451
Commercial paper		29,543		—		—			29,543
Corporate bonds		16,815		—		(189	)		16,626
U.S. government agency debt securities		3,353		8		—			3,361
Total short-term marketable securities	$	80,339	$	8	$	(366	)	$	79,981

All the U.S. Treasury securities, commercial paper, corporate bonds, and U.S. government agency debt securities designated as short-term marketable securities have a contractual maturity date that is equal to or less than one year from the respective balance sheet date.

Prior to 2023, the Company followed the guidance in ASC 320 Investments—Debt and Equity Securities in determining whether unrealized losses were other than temporary. The Company adopted Topic 326 on January 1, 2023, and now considers whether unrealized losses have resulted from a credit loss or other factors. The unrealized losses on the Company’s available-for-sale securities as of September 30, 2023 and December 31, 2022 were caused by fluctuations in market value and interest rates as a result of the economic environment. The Company concluded that an allowance for credit losses was unnecessary as of September 30, 2023 and that there were no impairments as of December 31, 2022 considered as other-than-temporary because the decline in the market value was attributable to changes in market conditions and not credit quality, and that it is neither management’s intention to sell nor is it more likely than not that the Company will be required to sell these investments prior to recovery of their cost basis or recovery of fair value. There was no material realized gain or loss on available-for-sale securities in the periods presented.

The Company elected the practical expedient to exclude accrued interest from both the fair value and the amortized cost basis of the available-for-sale debt securities for the purposes of identifying and measuring an impairment and to not measure an allowance for expected credit losses for accrued interest receivables. Accrued interest receivable is written off through net realized investment gains (losses) at the time the issuer of the bond defaults or is expected to default on payment. The Company made an accounting policy election to present the accrued interest receivable balance as part of prepaid expenses and other current assets in the condensed consolidated balance sheets. Accrued interest receivable related to marketable securities was $0.3 million and $0.1 million as of September 30, 2023 and December 31, 2022, respectively.

Investments in a continual unrealized loss position for less than 12 months consist of the following (in thousands):


	September 30, 2023		December 31, 2022
	Fair Value		Fair Value
U.S. Treasury securities	$	21,777	$	26,506
Corporate bonds		—		1,977
U.S. government agency debt securities		7,924		—
Total available-for-sale securities	$	29,701	$	28,483

Investments in a continual unrealized loss position for greater than 12 months consist of the following (in thousands):


	December 31, 2022
	Fair Value
Corporate bonds	$	14,649
U.S. Treasury securities		3,945
Total available-for-sale securities	$	18,594

The Company did not have any investments in a continual unrealized loss position for greater than 12 months as of September 30, 2023.