Available-for-Sale Marketable Securities and Fair Value Measurements

3 Months Ended

Mar. 31, 2024

Available For Sale Securities And Fair Value Measurements [Abstract]

Available-for-Sale Marketable Securities and Fair Value Measurements

The available-for-sale securities in our condensed consolidated balance sheets are as follows:


	March 31, 2024		December 31, 2023
	(in thousands)
Cash equivalents	$	112,895	$	97,170
Short-term marketable securities	261,011		232,670
Long-term marketable securities	40,276		57,176
Total marketable securities	$	414,182	$	387,016

The following table presents our available-for-sale securities grouped by asset type:


	Fair Value Hierarchy Level	March 31, 2024								December 31, 2023
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
		(in thousands)
Corporate bonds	Level 2	$	180,474	$	112	$	(64)	$	180,522	$	120,508	$	307	$	—	$	120,815
Commercial paper	Level 2	65,035		8		(15)		65,028		75,308		20		(9)		75,319
U.S. Treasury securities	Level 1	59,222		7		(3)		59,226		93,655		61		(4)		93,712
Money market funds	Level 1	109,406		—		—		109,406		97,170		—		—		97,170
Total marketable securities		$	414,137	$	127	$	(82)	$	414,182	$	386,641	$	388	$	(13)	$	387,016

We estimate the fair value of marketable securities classified as Level 1 using quoted market prices obtained from a commercial pricing service for these or identical investments. We estimate the fair value of marketable securities classified as Level 2 using inputs that may include benchmark yields, reported trades, broker/dealer quotes and issuer spreads.

We periodically review our debt securities to determine if any of our investments is impaired due to the issuer’s poor credit or other reasons. If the fair value of our investment is less than our amortized cost, we evaluate quantitative and subjective factors – including, but not limited to, the nature of security, changes in credit ratings and analyst reports concerning the security’s issuer and industry, and interest rate fluctuations and general market conditions – to determine whether an allowance for credit losses is appropriate.

None of our investments, including those with unrealized losses, are impaired. Unrealized losses on our investments are due to interest rate fluctuations. We do not intend to sell investments that currently have unrealized losses and it is highly unlikely that we will sell any investment before recovery of its amortized cost basis, which may be at maturity. Accordingly, we have not recorded an allowance for credit losses for these investments.

We classified accrued interest on our marketable securities of $2.0 million and $1.7 million as of March 31, 2024 and December 31, 2023, respectively, as prepaid and other current assets on our condensed consolidated balance sheets.

As of March 31, 2024, all of our long-term marketable securities had original maturities of no more than 27 months and all our marketable securities classified as short-term have maturities of less than one year. The weighted-average maturity of our holdings was 6 months. As of March 31, 2024, our long-term marketable securities had remaining maturities between 12 months and 19 months. None of our marketable securities changed from one fair value hierarchy to another during the three months ended March 31, 2024.