Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Operating expenses
Research and development	$ 58,852	$ 26,711
General and administrative	80,442	26,090
Total operating expenses	139,294	52,801
Loss from operations	(139,294)	(52,801)
Other income (loss)
Change in fair value of simple agreements for future equity	0	(27,864)
Interest and dividend income, net	29,102	7,732
Total other income (loss)	29,102	(20,132)
Loss before income taxes	(110,192)	(72,933)
Income tax benefit (expense)	4,529	(683)
Net loss	$ (105,663)	$ (73,616)
Net loss per share:
Basic - Class A common stock (in dollars per share)	$ (0.72)	$ (0.74)
Diluted - Class A common stock (in dollars per share)	$ (0.72)	$ (0.74)
Weighted-average common shares outstanding - basic - Class A common stock (in shares)	146,351,775	98,910,013
Weighted-average common shares outstanding - diluted - Class A common stock (in shares)	146,351,775	98,910,013

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
Consolidated Statements of Cash Flows - USD ($)	Dec. 31, 2025	Dec. 31, 2024
Cash flows from operating activities:
Net loss	$ (105,663,000)	$ (73,616,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	522,000	268,000
Change in fair value of simple agreements for future equity	0	27,864,000
Interest income and accretion of discount on marketable debt securities, net	(3,485,000)	(520,000)
Stock-based compensation	41,795,000	12,484,000
Deferred income taxes	(4,529,000)	0
Change in operating assets and liabilities, net of effect of acquisition:
Prepaid and other current assets	(21,574,000)	(1,520,000)
Other assets	(77,000)	(115,000)
Accounts payable	(1,532,000)	(1,762,000)
Accrued expenses and other	12,345,000	(1,504,000)
Operating lease right-of-use assets and liabilities	24,000	31,000
Net cash used in operating activities	(82,174,000)	(38,390,000)
Cash flows from investing activities:
Purchases of property, plant and equipment	(33,205,000)	(352,000)
Purchases of marketable debt securities	(820,480,000)	(291,620,000)
Proceeds from redemptions of marketable debt securities	376,992,000	116,198,000
Payment for acquisition of business, net of cash acquired	(900,000)	0
Purchase of other investments	(12,086,000)	0
Net cash used in investing activities	(489,679,000)	(175,774,000)
Cash flows from financing activities:
Proceeds from recapitalization	0	276,210,000
Payment of taxes from common stock withheld	(1,647,000)	0
Proceeds from exercise of stock options	4,028,000	1,044,000
Proceeds from right of first refusal liability	0	25,000,000
Proceeds from simple agreements for future equity	0	10,232,000
Payment of offering costs and deferred issuance costs	(2,814,000)	(11,058,000)
Proceeds from sale of common stock, net of offering costs	1,263,599,000	0
Net cash provided by financing activities	1,263,166,000	301,428,000
Net increase in cash and cash equivalents	691,313,000	87,264,000
Cash and cash equivalents - beginning of year	97,132,000	9,868,000
Cash and cash equivalents - end of year	788,445,000	97,132,000
Supplemental noncash investing and financing activities:
Issuance of common stock in connection with acquisition of business	27,408,000	0
Assumed liabilities in connection with acquisition of business	287,000	0
Offering costs included in accounts payable	79,000	0
Offering costs included in accrued expense and other	240,000	0
Deferred issuance costs included in accounts payable	0	1,906,000
Reclassification of simple agreements for future equity in connection with the Recapitalization	0	84,138,000
Reclassification of deferred issuance costs in connection with Recapitalization	0	5,510,000
Property, Plant and Equipment
Supplemental noncash investing and financing activities:
Purchases of property, plant and equipment and computer software in accounts payable and accrued expense and other	8,387,000	0
Software
Supplemental noncash investing and financing activities:
Purchases of property, plant and equipment and computer software in accounts payable and accrued expense and other	$ 0	$ 540,000

Consolidated Balance Sheets - USD ($)	Dec. 31, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 788,445,000	$ 97,132,000
Marketable debt securities	439,526,000	130,682,000
Prepaid and other current assets	25,798,000	4,125,000
Total current assets	1,253,769,000	231,939,000
Marketable debt securities, net of current portion	184,568,000	47,473,000
Property, plant and equipment, net	42,312,000	1,202,000
Operating lease right-of-use assets	1,384,000	982,000
Indefinite-lived intangible assets	27,500,000	0
Goodwill	6,621,000	0
Other assets	12,303,000	140,000
Total assets	1,528,457,000	281,736,000
Current liabilities:
Accounts payable	4,145,000	2,970,000
Accrued expenses and other	20,497,000	1,885,000
Operating lease liabilities	904,000	481,000
Total current liabilities	25,546,000	5,336,000
Operating lease liabilities, net of current portion	546,000	543,000
Right of first refusal liability	25,000,000	25,000,000
Deferred tax liabilities	1,155,000	0
Total liabilities	52,247,000	30,879,000
Commitments and contingencies
Stockholders' equity:
Class A common stock, $0.0001 par value – 500,000,000 shares authorized; 160,514,103 and 137,706,596 shares issued and outstanding as of December 31, 2025 and 2024, respectively	16,000	14,000
Additional paid-in capital	1,715,787,000	383,739,000
Accumulated deficit	(240,772,000)	(135,109,000)
Accumulated other comprehensive income	1,179,000	2,213,000
Total stockholders’ equity	1,476,210,000	250,857,000
Total liabilities and stockholders’ equity	$ 1,528,457,000	$ 281,736,000