Consolidated Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (111,905)	$ (18,499)	$ (9,712)
Adjustments to reconcile net loss to net cash (used in) provided by operations:
Share-based compensation	57,924	12,231	4,906
Depreciation and amortization	6,026	5,390	2,406
Transaction expenses related to the Merger	3,132	0	0
Amortization of right-of-use assets	3,999	2,804	1,638
Loss on impairment of long lived assets	446	0	0
Bad debt reserve	433	121	424
Change in fair value of warrant liabilities	(19,836)	6,064	292
Settlement of related party promissory notes	5,517	0	0
Other	0	107	462
Changes in operating assets and liabilities:
Accounts receivable	1,403	382	(3,386)
Prepaid expenses and other assets	(3,321)	(1,031)	(2,191)
Accounts payable	904	(692)	(1,683)
Accrued expenses and other liabilities	(788)	(520)	2,138
Accrued compensation and benefits	(7,911)	8,080	3,869
Operating lease liabilities	(4,829)	(3,536)	(1,691)
Net cash (used in) provided by operating activities	(68,806)	10,901	(2,528)
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired	0	0	(13,114)
Purchases of property and equipment	(220)	0	(13)
Purchases of intangible assets	(118)	(2,202)	0
Capitalized internal-use software development costs	(6,312)	(1,054)	(1,149)
Loan to SharesPost	0	0	(3,000)
Payment of deferred payments related to IRA Services acquisition	0	0	(6,097)
Net cash used in investing activities	(6,650)	(3,256)	(23,373)
Cash flows from financing activities:
Proceeds from the Merger	7,865	0	0
Proceeds from PIPE investment and A&R FPA investors	208,500	0	0
Payments for offering costs	(56,852)	(4,954)	0
Proceeds from exercise of Public Warrants	22,940	0	0
Proceeds from notes payable	0	0	25,566
Formation of Forge Europe	9,488	0	0
Proceeds from exercise of options, including proceeds from repayment of promissory notes	1,086	1,621	24
Payments for redemption of Public Warrants	(165)	0	0
Repayment of notes payable	0	(19,438)	(27,688)
Cash paid to purchase equity awards	0	(23)	(49)
Net cash provided by financing activities	192,862	26,581	39,380
Effect of changes in currency exchange rates on cash and cash equivalents	1,155	0	0
Net increase in cash and cash equivalents	118,561	34,226	13,479
Cash, cash equivalents and restricted cash, beginning of the period	76,404	42,178	28,699
Cash, cash equivalents and restricted cash, end of the period	194,965	76,404	42,178
Reconciliation of cash, cash equivalents and restricted cash to the amounts reported within the consolidated balance sheets
Cash and cash equivalents	193,136	74,781	40,577
Restricted cash	1,829	1,623	1,601
Total cash, cash equivalents and restricted cash, end of the period	194,965	76,404	42,178
Supplemental disclosures of cash flow information:
Cash paid for interest	0	2,118	425
Supplemental disclosure of non-cash investing and financing activities:
Lease liabilities arising from obtaining right-of-use assets	3,087	1,702	0
Capitalized internal-use software development costs accrued and not yet paid	180	214	0
Deferred payments related to SharesPost acquisition	0	0	783
Forgiveness of loan to SharesPost in relation to acquisition	0	0	3,000
Reclassification of deferred offering costs to equity	5,923	0	0
Conversion of preferred stock	246,049	0	0
Conversion of May 2020 and October 2020 preferred stock warrants of Legacy Forge to common stock warrants	2,949	0	0
Non-cash assets acquired in the Merger	193	0	0
Warrants issued in connection with A&R FPA	3,080	0	0
Assumption of merger warrants liability	13,983	0	0
Exchange of Class AA common stock for Series B-1 convertible preferred stock	0	39,722	0
Vesting of early exercised stock options and restricted stock awards	1,554	145	32
Warrant liability reclassified to additional paid-in capital upon exercise of Public Warrants	698	0	0
Warrant liability reclassified to additional paid-in capital upon exercise of Junior Preferred Stock Warrants	653	0	0
Issuance of common stock upon settlement of related party promissory notes	4,207	0	0
Early exercise of stock options upon settlement of related party promissory notes	1,310	0	0
Deferred offering cost accrued and not yet paid	0	969	0
Warrant issued in connection with issuance of convertible notes payable	0	0	51
Warrant issued in connection with issuance of term loan	0	0	151
Series B-1
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	0	47,735	41,527
Supplemental disclosure of non-cash investing and financing activities:
Conversion of convertible notes into Series B-1 convertible preferred stock	0	111	9,940
Series B-2
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	0	1,640	0
Junior Convertible Preferred Stock
Supplemental disclosure of non-cash investing and financing activities:
Issuance of stock in relation to acquisition	0	0	20,383
Junior Convertible Preferred Stock Warrants
Supplemental disclosure of non-cash investing and financing activities:
Issuance of stock in relation to acquisition	0	0	1,285
Class AA Common Stock
Supplemental disclosure of non-cash investing and financing activities:
Issuance of stock in relation to acquisition	$ 0	$ 0	$ 44,817