Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Conversion Of Redeemable Convertible Preferred Stock To Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Conversion Of Redeemable Convertible Preferred Stock To Common Stock	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Class A	Class A Common Stock	Class A Common Stock Conversion Of Class B Common Stock To Class A Common Stock	Class A Common Stock Conversion Of Redeemable Convertible Preferred Stock To Common Stock	Class B	Class B Conversion Of Class B Common Stock To Class A Common Stock	Class B Common Stock	Class B Common Stock Conversion Of Class B Common Stock To Class A Common Stock	Class B Common Stock Conversion Of Redeemable Convertible Preferred Stock To Common Stock
Beginning balance (in shares) at Dec. 31, 2023	73,021,449
Beginning balance at Dec. 31, 2023	$ 1,853,492
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)	(73,021,449)
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	$ (1,853,492)
Ending balance (in shares) at Jun. 30, 2024	0
Ending balance at Jun. 30, 2024	$ 0
Beginning balance (in shares) at Dec. 31, 2023								7,099,700					53,904,204
Beginning balance at Dec. 31, 2023	(412,922)		$ 302,820		$ 814	$ (716,562)		$ 0					$ 6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net (in shares)								3,394,138					813,648
Issuance of common stock upon exercise of stock options, net	24,932		24,932
Issuance of common stock upon settlement of restricted stock units, net (in shares)								8,162,928					661,497
Issuance of common stock upon settlement of restricted stock units, net	(202,852)		(202,853)					$ 1
Conversion of stock (in shares)									20,142,152	5,104,017				(20,142,152)	67,917,432
Conversion of stock		$ 1,853,494		$ 1,853,486					$ 2	$ 1		$ 0		$ (2)	$ 7
Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs (in shares)								18,576,527
Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs	576,268		576,266					$ 2
Stock-based compensation expense	641,774		641,774
Vesting of early exercised stock options	124		124
Net income (loss)	(585,165)					(585,165)
Change in other comprehensive income (loss)	(1,818)				(1,818)
Ending balance (in shares) at Jun. 30, 2024								62,479,462					103,154,629
Ending balance at Jun. 30, 2024	$ 1,893,835		3,196,549		(1,004)	(1,301,727)		$ 6					$ 11
Ending balance (in shares) at Jun. 30, 2024	0
Ending balance at Jun. 30, 2024	$ 0
Beginning balance (in shares) at Mar. 31, 2024								44,286,735					119,059,756
Beginning balance at Mar. 31, 2024	1,838,300		3,130,384		(472)	(1,291,628)		$ 4					$ 12
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net (in shares)								252,962					7,700
Issuance of common stock upon exercise of stock options, net	1,843		1,843
Issuance of common stock upon settlement of restricted stock units, net (in shares)								1,989,556					37,382
Conversion of stock (in shares)									15,950,209					(15,950,209)
Conversion of stock		$ 2		$ 1					$ 2			0		$ (2)	$ 1
Stock-based compensation expense	64,266		64,266
Vesting of early exercised stock options	55		55
Net income (loss)	(10,099)					(10,099)
Change in other comprehensive income (loss)	(532)				(532)
Ending balance (in shares) at Jun. 30, 2024								62,479,462					103,154,629
Ending balance at Jun. 30, 2024	$ 1,893,835		3,196,549		(1,004)	(1,301,727)		$ 6					$ 11
Beginning balance (in shares) at Dec. 31, 2024	0
Beginning balance at Dec. 31, 2024	$ 0
Ending balance (in shares) at Jun. 30, 2025	0
Ending balance at Jun. 30, 2025	$ 0
Beginning balance (in shares) at Dec. 31, 2024							125,001,880	125,001,880			55,314,099		55,314,099
Beginning balance at Dec. 31, 2024	$ 2,130,749		3,331,546		24	(1,200,838)		$ 12					$ 5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net (in shares)	2,819,924							1,363,474					1,456,450
Issuance of common stock upon exercise of stock options, net	$ 14,487		14,487
Issuance of common stock upon settlement of restricted stock units, net (in shares)								3,904,250					34,502
Issuance of common stock upon settlement of restricted stock units, net	(51,898)		(51,899)					$ 1
Conversion of stock (in shares)									1,692,925					(1,692,925)
Conversion of stock									$ 0			$ 0		$ 0
Stock-based compensation expense	174,484		174,484
Net income (loss)	115,455					115,455
Change in other comprehensive income (loss)	3,703				3,703
Ending balance (in shares) at Jun. 30, 2025							131,962,529	131,962,529			55,112,126		55,112,126
Ending balance at Jun. 30, 2025	$ 2,386,980		3,468,618		3,727	(1,085,383)		$ 13					$ 5
Ending balance (in shares) at Jun. 30, 2025	0
Ending balance at Jun. 30, 2025	$ 0
Beginning balance (in shares) at Mar. 31, 2025								129,145,465					55,121,821
Beginning balance at Mar. 31, 2025	2,217,121		3,390,469		1,314	(1,174,680)		$ 13					$ 5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net (in shares)								358,393					629,769
Issuance of common stock upon exercise of stock options, net	4,303		4,303
Issuance of common stock upon settlement of restricted stock units, net (in shares)								1,801,956					17,251
Issuance of common stock upon settlement of restricted stock units, net	(15,224)		(15,224)					$ 0
Conversion of stock (in shares)									656,715					(656,715)
Stock-based compensation expense	89,070		89,070
Net income (loss)	89,297					89,297
Change in other comprehensive income (loss)	2,413				2,413
Ending balance (in shares) at Jun. 30, 2025							131,962,529	131,962,529			55,112,126		55,112,126
Ending balance at Jun. 30, 2025	$ 2,386,980		$ 3,468,618		$ 3,727	$ (1,085,383)		$ 13					$ 5