Condensed Consolidated Statement of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Revenues:
Total revenues	$ 339,778	$ 276,656	$ 994,639	$ 816,176
Cost of revenues:
Liquidity payments	217,286	167,797	606,983	525,399
Brokerage, clearing, and exchange fees	11,612	17,731	42,547	51,134
Section 31 fees	0	20,241	35,225	40,108
Equity rights program	0	0	0	1,975
Other cost of revenues	1,397	1,329	3,855	3,621
Total cost of revenues	230,295	207,098	688,610	622,237
Revenues less cost of revenues	109,483	69,558	306,029	193,939
Operating expenses:
Compensation and benefits	68,753	37,850	146,734	107,227
Information technology and communication costs	9,290	7,250	25,689	21,442
Depreciation and amortization	8,229	6,045	21,337	17,107
Occupancy costs	3,568	2,335	9,018	7,032
Professional fees and outside services	10,807	12,658	30,159	34,663
Marketing and business development	759	663	2,077	2,198
Acquisition-related costs	0	0	2,901	0
General, administrative, and other	8,382	3,916	18,835	14,253
Total operating expenses	109,788	70,717	256,750	203,922
Operating income (loss)	(305)	(1,159)	49,279	(9,983)
Non-operating (expense) income:
Change in fair value of puttable common stock	(338)	(6,791)	(2,229)	(8,149)
Change in fair value of puttable warrants issued with debt	(255)	(1,635)	(1,172)	(1,635)
Interest income	2,658	840	5,371	1,976
Interest expense and amortization of debt issuance costs	(3,378)	(2,208)	(12,710)	(9,532)
Gain (loss) on sale of intangible asset	0	0	(2,054)	52,604
Unrealized gain (loss) on derivative assets	7,979	10,010	(39,039)	76,684
Loss on debt extinguishment	(107,656)	0	(107,656)	0
Other, net	(1,595)	(703)	10,765	(149)
Income (loss) before income tax provision	(102,890)	(1,646)	(99,445)	101,816
Income tax (expense) benefit	810	(1,559)	(528)	(2,721)
Net income (loss)	(102,080)	(3,205)	(99,973)	99,095
Net loss attributable to non-controlling interest	0	(1)	0	(137)
Net income (loss) attributable to Miami International Holdings, Inc.	$ (102,080)	$ (3,204)	$ (99,973)	$ 99,232
Weighted-average shares of common stock outstanding
Basic (in shares)	70,128,197	63,246,820	66,168,315	60,477,992
Diluted (in shares)	70,128,197	63,246,820	66,168,315	75,212,560
Net income (loss) per share attributable to common stock
Basic (in dollars per share)	$ (1.46)	$ (0.05)	$ (1.51)	$ 1.64
Diluted (in dollars per share)	$ (1.46)	$ (0.05)	$ (1.51)	$ 1.35
Transaction and clearing fees
Revenues:
Total revenues	$ 292,814	$ 240,623	$ 868,257	$ 712,209
Access fees
Revenues:
Total revenues	27,096	22,490	77,285	66,787
Market data fees
Revenues:
Total revenues	10,730	9,143	30,625	24,808
Other revenue
Revenues:
Total revenues	$ 9,138	$ 4,400	$ 18,472	$ 12,372