Financial Instruments

3 Months Ended

Mar. 31, 2025

Financial Instruments Pledged as Collateral [Abstract]

Financial Instruments

(3)Financial Instruments

Investments

Cullinan recognized its investments by security type at March 31, 2025 as follows (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Short-term investments
Corporate notes	$	148,703	$	64	$	(49	)	$	148,718
U.S. government notes		78,380		78		(2	)		78,456
Total short-term investments		227,083		142		(51	)		227,174
Long-term investments
U.S. government notes		149,244		577		(16	)		149,805
Corporate notes		70,261		37		(209	)		70,089
Asset-backed securities		39,465		44		(19	)		39,490
Total long-term investments		258,970		658		(244	)		259,384
Total investments	$	486,053	$	800	$	(295	)	$	486,558

Cullinan recognized its investments by security type at December 31, 2024 as follows (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Short-term investments
Corporate notes	$	211,584	$	343	$	(6	)	$	211,921
U.S. government notes		78,874		81		—			78,955
Asset-backed securities		25,084		12		—			25,096
Total short-term investments		315,542		436		(6	)		315,972
Long-term investments
U.S. government notes		118,423		88		(188	)		118,323
Corporate notes		77,196		9		(472	)		76,733
Asset-backed securities		9,384		—		—			9,384
Total long-term investments		205,003		97		(660	)		204,440
Total investments	$	520,545	$	533	$	(666	)	$	520,412

Fair Value of Financial Instruments

The following table sets forth the fair value of Cullinan’s financial assets that were measured at fair value on a recurring basis as of March 31, 2025 (in thousands):

	Level 1		Level 2		Level 3		Total
Short-term investments
Corporate notes	$	—	$	148,718	$	—	$	148,718
U.S. government notes		—		78,456		—		78,456
Total short-term investments		—		227,174		—		227,174
Long-term investments
U.S. government notes		—		149,805		—		149,805
Corporate notes		—		70,089		—		70,089
Asset-backed securities		—		39,490		—		39,490
Total long-term investments		—		259,384		—		259,384
Total investments	$	—	$	486,558	$	—	$	486,558

The following table sets forth the fair value of the Company’s financial assets that were measured at fair value on a recurring basis as of December 31, 2024 (in thousands):

	Level 1		Level 2		Level 3		Total
Short-term investments
Corporate notes	$	—	$	211,921	$	—	$	211,921
U.S. government notes		—		78,955		—		78,955
Asset-backed securities		—		25,096		—		25,096
Total short-term investments		—		315,972		—		315,972
Long-term investments
U.S. government notes		—		118,323		—		118,323
Corporate notes		—		76,733		—		76,733
Asset-backed securities		—		9,384		—		9,384
Total long-term investments		—		204,440		—		204,440
Total investments	$	—	$	520,412	$	—	$	520,412

As of March 31, 2025 and December 31, 2024, the fair values of Cullinan's cash and cash equivalents, prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities approximated their carrying values due to the short-term nature of these instruments.