Miami International Holdings MIAX Institutional Ownership

NYSE MIAX

$34.90 +1.32 (+3.93%)

As of: Oct 22, 2026 · 3:59 PM EDT

Institutions by Trading Activity

207 Institutions

Increased 142 68.6%

Unchanged 19 9.2%

Reduced 46 22.2%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

72.77%

▲+19.28 pp QoQ

Shares Held by Institutions

71.75Mn

of 98.61Mn outstanding

▲+42.40% QoQ

Shares Outstanding

98.61Mn

26.86Mn held outside 13F filers

Institutional Investors

207

filed 13F for Jun 2026

▲+7 vs prior quarter

Net Shares Added (QoQ)

+21.36Mn

accumulated since last quarter

Value of Holdings

$2.41Bn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 11, 2026

Miami International Holdings, Inc. (NYSE:MIAX) was reported as a holding by 207 institutional investors in 13F filings for the quarter ended June 30, 2026.

Together they owned 72.77% of the outstanding stock in Q2 2026, up from 53.49% a quarter earlier.
Total shares held in Miami International Holdings rose 42.40% versus Q1 2026.
Among the 207 holders of Miami International Holdings, 142 added to their positions, 46 reduced their stakes and 19 left their positions unchanged.
In total, institutional investors held 71.75Mn shares of Miami International Holdings at the end of Q2 2026, up 21.36Mn from the prior quarter.
Horizon Kinetics Asset Management LLC was the top holder of Miami International Holdings as of June 30, 2026, with 7.84Mn shares, or 7.95% of shares outstanding.
The largest position increases in MIAX for Q2 2026 were by Horizon Kinetics Asset Management LLC (+4.39Mn shares), BlackRock, Inc. (+2.84Mn shares), Vanguard Portfolio Management LLC (+2.41Mn shares), Vanguard Capital Management LLC (+1.75Mn shares) and Blair William & Co (+1.1Mn shares).
The largest position reductions in MIAX for Q2 2026 were by North Reef Capital Management LP (-762.92K shares), Alyeska Investment Group, L.P. (-598.7K shares), Ghisallo Capital Management LLC (-500K shares), Millennium Management LLC (-329.6K shares) and Allspring Global Investments Holdings, LLC (-254.58K shares).
Per Business Quant data, the 10 largest holders of Miami International Holdings at the end of Q2 2026 were Horizon Kinetics Asset Management LLC (7.84Mn shares), BlackRock, Inc. (5.07Mn shares), T. Rowe Price Investment Management, Inc. (5.03Mn shares), Vanguard Portfolio Management LLC (3.79Mn shares), Susquehanna International Group, LLP (3.36Mn shares), Vanguard Capital Management LLC (3.17Mn shares), Invesco Ltd. (2.02Mn shares), J Digital 6 LLC (1.81Mn shares), Blair William & Co (1.77Mn shares) and Balyasny Asset Management L.P. (1.68Mn shares).

Form 13F Holdings

208 Institutional Holders

Report period 30 Jun, 2026

Total shares held 71.75Mn

Of outstanding 72.77%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	HORIZON KINETICS ASSET MANAGEMENT LLC	0001056823	7,842,173	7.95%	▲4,390,624	+127.21%	$291.42Mn
2	BlackRock, Inc.	0002012383	5,071,754	5.14%	▲2,839,074	+127.16%	$188.47Mn
3	T. Rowe Price Investment Management, Inc.	0001897612	5,032,970	5.10%	▲887,352	+21.40%	$187.03K
4	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	3,786,418	3.84%	▲2,411,472	+175.39%	$140.70Mn
5	SUSQUEHANNA INTERNATIONAL GROUP, LLP	0001446194	3,355,043	3.40%	▲58,697	+1.78%	$124.67Mn
6	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	3,165,686	3.21%	▲1,750,707	+123.73%	$117.64Mn
7	Invesco Ltd.	0000914208	2,020,650	2.05%	▲435,647	+27.49%	$75.09Mn
8	J Digital 6 LLC	0002090663	1,807,234	1.83%	▲1,807,234	0.00%	$67.16Mn
9	BLAIR WILLIAM & CO/IL	0000902367	1,769,432	1.79%	▲1,103,651	+165.77%	$65.75Mn
10	BALYASNY ASSET MANAGEMENT L.P.	0001218710	1,682,924	1.71%	▲1,682,924	0.00%	$62.54Mn
11	AMERICAN CENTURY COMPANIES INC	0000748054	1,587,196	1.61%	▲365,711	+29.94%	$58.98Mn
12	State Street Corp	0000093751	1,432,894	1.45%	▲720,565	+101.16%	$53.25Mn
13	Jpmorgan Chase & Co	0000019617	1,427,881	1.45%	▲189,875	+15.34%	$52.72Mn
14	GEODE CAPITAL MANAGEMENT, LLC	0001214717	1,395,680	1.42%	▲615,898	+78.98%	$51.87Mn
15	ADAGE CAPITAL PARTNERS GP, L.L.C.	0001165408	1,143,920	1.16%	▼103,079	-8.27%	$42.51Mn
16	HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND	0001535845	1,039,449	1.05%	▲799,449	+333.10%	$38.63Mn
17	LORD, ABBETT & CO. LLC	0000728100	1,000,866	1.01%	▲140,179	+16.29%	$37.19K
18	Morgan Stanley	0000895421	950,593	0.96%	▼196,363	-17.12%	$35.32Mn
19	TWO SIGMA INVESTMENTS, LP	0001179392	888,109	0.90%	▼5,609	-0.63%	$33.00Mn
20	Allspring Global Investments Holdings, LLC	0001890906	857,682	0.87%	▼254,579	-22.89%	$33.49Mn

Showing 1 to 20 of 208 holders