Financial Instruments

6 Months Ended

Jun. 30, 2026

Financial Instruments Pledged as Collateral [Abstract]

(3)

Financial Instruments

Investments

The following table summarizes Cullinan’s investments by security type at June 30, 2026 (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Short-term investments:
U.S. government notes	$	129,965	$	142	$	—		$	130,107
Corporate notes		116,050		11		(166	)		115,895
Asset-backed securities		9,887		9		—			9,896
Total short-term investments		255,902		162		(166	)		255,898
Long-term investments:
Corporate notes		19,150		—		(130	)		19,020
Total long-term investments		19,150		—		(130	)		19,020
Total investments	$	275,052	$	162	$	(296	)	$	274,918

The following table summarizes Cullinan’s investments by security type at December 31, 2025 (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Short-term investments:
U.S. government notes	$	159,632	$	683	$	—		$	160,315
Corporate notes		119,368		119		(7	)		119,480
Asset-backed securities		9,717		52		—			9,769
Total short-term investments		288,717		854		(7	)		289,564
Long-term investments:
Corporate notes		48,134		90		(2	)		48,222
U.S. government notes		9,963		85		—			10,048
Total long-term investments		58,097		175		(2	)		58,270
Total investments	$	346,814	$	1,029	$	(9	)	$	347,834

All of the Company's long-term investments as of June 30, 2026 and December 31, 2025 had maturities between one and two years from the respective balance sheet dates. The Company did not record any allowances for credit losses relating to its investments during the three and six months ended June 30, 2026 and 2025.

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 June 30, 2026 (in thousands):


	Level 1		Level 2		Level 3		Total
Short-term investments:
U.S. government notes	$	—	$	130,107	$	—	$	130,107
Corporate notes		—		115,895		—		115,895
Asset-backed securities		—		9,896		—		9,896
Total short-term investments		—		255,898		—		255,898
Long-term investments:
Corporate notes		—		19,020		—		19,020
Total long-term investments		—		19,020		—		19,020
Total investments	$	—	$	274,918	$	—	$	274,918

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, 2025 (in thousands):


	Level 1		Level 2		Level 3		Total
Short-term investments
U.S. government notes	$	—	$	160,315	$	—	$	160,315
Corporate notes		—		119,480		—		119,480
Asset-backed securities		—		9,769		—		9,769
Total short-term investments		—		289,564		—		289,564
Long-term investments
Corporate notes		—		48,222		—		48,222
U.S. government notes		—		10,048		—		10,048
Total long-term investments		—		58,270		—		58,270
Total investments	$	—	$	347,834	$	—	$	347,834

As of June 30, 2026 and December 31, 2025, 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.