We invest in available-for-sale securities consisting of U.S. Treasury securities, U.S. Agency bonds and money market funds. Available-for-sale securities are classified as either cash and cash equivalents or short-term investments on the unaudited condensed balance sheets.

The following tables summarize, by major security type, our short-term investments that are measured at fair value on a recurring basis, in thousands:


		June 30, 2026
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Cash equivalents
Money market funds	1 or less	$	15,595	$	—	$	—		$	15,595

Short-term investments
U.S. Treasury securities	2 or less		400,000		102		(976	)		399,126
U.S. Agency bonds	3 or less		49,996		—		(339	)		49,657
Total short-term investments			449,996		102		(1,315	)		448,783
Total		$	465,591	$	102	$	(1,315	)	$	464,378


		December 31, 2025
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Cash equivalents
Money market funds	1 or less	$	119,910	$	—	$	—		$	119,910

Short-term investments
U.S. Treasury securities	2 or less		464,623		1,042		—			465,665
U.S. Agency bonds	3 or less		52,494		11		(29	)		52,476
Total short-term investments			517,117		1,053		(29	)		518,141
Total		$	637,027	$	1,053	$	(29	)	$	638,051

Short-term investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund our operations, as necessary. As of June 30, 2026 and December 31, 2025, short-term investments of $306.9 million and $367.2 million, respectively, had maturities less than one year, short-term investments of $124.5 million and $135.9 million, respectively, had maturities between one to two years, and short-term investments of $17.4 million and $15.0 million, respectively, had maturities between two to three years. Realized gains and losses were de minimis for the three and six months ended June 30, 2026 and 2025.

As of June 30, 2026 and December 31, 2025, 55 available-for-sale securities with a fair market value of $406.3 million and six available-for-sale securities with a fair market value of $22.5 million, respectively, were in a gross unrealized loss position. None of such securities were in a continuous unrealized loss position for greater than 12 months. We do not intend to sell such available-for-sale securities, and it is not more likely than not that we will be required to sell such securities prior to recovery of their amortized cost basis. Based on our review of these available-for-sale securities, the unrealized losses at June 30, 2026 were primarily due to changes in interest rates and not due to increased credit risks associated with specific securities. As such we have no allowance for credit losses as of June 30, 2026 and December 31, 2025. Unrealized gains and losses that are not credit-related are included in accumulated other comprehensive income (loss).

Accrued interest receivable on available-for-sale securities was $3.6 million and $3.8 million as of June 30, 2026 and December 31, 2025, respectively. We have not written off any accrued interest receivables for the six months ended June 30, 2026 and 2025.