MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) Institutional Shareholders
MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026. The institutional investors covered on this page collectively reported approximately $2.64B in MIAX holdings during the latest filing period.
Horizon Kinetics Asset Management Llc is currently the largest disclosed institutional shareholder of MIAX tracked by InsiderSet, reporting ownership valued at approximately $291.42M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $304.20M, representing an estimated gain of +4.39% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 50% of the total disclosed MIAX value among the investors covered in this analysis. Major shareholders include Horizon Kinetics Asset Management Llc, Blackrock, Inc., T. Rowe Price Investment Management, Inc., and several other long-term asset managers with concentrated positions in MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX).
This page ranks the largest institutional MIAX shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
201
Total Reported Value
$2.64B
Largest Holder
Horizon Kinetics Asset Management Llc
Largest Position
$291.42M
Insider Transactions (90d)
0
Latest Filing Quarter
Q2 2026
New Institutional Positions
105
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Horizon Kinetics Asset Management Llc | 3.30% | 7,842,173 | $291,415,166 | $304,197,891 | +$12,782,725 | +4.39% | |
| Blackrock, Inc. | 0.00% | 5,071,754 | $188,466,378 | $196,733,338 | +$8,266,960 | +4.39% | |
| T. Rowe Price Investment Management, Inc. | 0.12% | 5,032,970 | $187,026,000 | $195,228,906 | +$8,202,906 | +4.39% | |
| Vanguard Portfolio Management Llc | 0.01% | 3,786,418 | $140,703,293 | $146,875,154 | +$6,171,861 | +4.39% | |
| Susquehanna International Group, Llp | 0.11% | 3,355,043 | $124,673,398 | $130,142,118 | +$5,468,720 | +4.39% | |
| Vanguard Capital Management Llc | 0.00% | 3,165,686 | $117,636,892 | $122,796,960 | +$5,160,068 | +4.39% | |
| Invesco Ltd. | 0.01% | 2,020,650 | $75,087,354 | $78,381,014 | +$3,293,660 | +4.39% | |
| J Digital 6 Llc | 39.72% | 1,807,234 | $67,156,815 | $70,102,607 | +$2,945,792 | +4.39% | |
| Blair William & Co/Il | 0.17% | 1,769,432 | $65,752,093 | $68,636,267 | +$2,884,174 | +4.39% | |
| Balyasny Asset Management L.P. | 0.11% | 1,682,924 | $62,537,456 | $65,280,622 | +$2,743,166 | +4.39% | |
| American Century Companies Inc | 0.03% | 1,587,196 | $58,980,261 | $61,567,333 | +$2,587,072 | +4.39% | |
| State Street Corp | 0.00% | 1,432,894 | $53,246,341 | $55,581,958 | +$2,335,617 | +4.39% | |
| Jpmorgan Chase & Co | 0.00% | 1,427,881 | $52,718,389 | $55,387,504 | +$2,669,115 | +5.06% | |
| Geode Capital Management, Llc | 0.00% | 1,395,680 | $51,869,678 | $54,138,427 | +$2,268,749 | +4.37% | |
| Adage Capital Partners Gp, L.L.C. | 0.06% | 1,143,920 | $42,508,067 | $44,372,657 | +$1,864,590 | +4.39% | |
| Healthcare Of Ontario Pension Plan Trust Fund | 0.06% | 1,039,449 | $38,625,925 | $40,320,227 | +$1,694,302 | +4.39% | |
| Lord, Abbett & Co. Llc | 0.11% | 1,000,866 | $37,192,000 | $38,823,592 | +$1,631,592 | +4.39% | |
| Morgan Stanley | 0.00% | 950,593 | $35,324,037 | $36,873,502 | +$1,549,465 | +4.39% | |
| Allspring Global Investments Holdings, Llc | 0.05% | 857,682 | $33,492,482 | $33,269,485 | -$222,997 | -0.67% | |
| Two Sigma Investments, Lp | 0.02% | 888,109 | $33,002,130 | $34,449,748 | +$1,447,618 | +4.39% | |
| Bank Of America Corp | 0.00% | 856,980 | $31,845,377 | $33,242,254 | +$1,396,877 | +4.39% | |
| Alyeska Investment Group, L.P. | 0.08% | 848,750 | $31,539,550 | $32,923,013 | +$1,383,463 | +4.39% | |
| Price T Rowe Associates Inc | 0.00% | 844,464 | $31,381,000 | $32,756,759 | +$1,375,759 | +4.38% | |
| Walleye Capital Llc | 0.13% | 728,034 | $27,053,743 | $28,240,439 | +$1,186,696 | +4.39% | |
| Westfield Capital Management Co Lp | 0.09% | 700,741 | $26,039,536 | $27,181,743 | +$1,142,207 | +4.39% | |
| Newedge Advisors, Llc | 0.08% | 681,610 | $25,328,627 | $26,439,652 | +$1,111,025 | +4.39% | |
| Nuveen, Llc | 0.01% | 668,115 | $24,827,154 | $25,916,181 | +$1,089,027 | +4.39% | |
| Caldwell Investment Management Ltd. | 14.63% | 600,000 | $22,279,367 | $23,274,000 | +$994,633 | +4.46% | |
| Ubs Group Ag | 0.00% | 567,797 | $21,099,336 | $22,024,846 | +$925,510 | +4.39% | |
| Driehaus Capital Management Llc | 0.12% | 566,052 | $21,034,492 | $21,957,157 | +$922,665 | +4.39% | |
| Northern Trust Corp | 0.00% | 562,337 | $20,896,443 | $21,813,052 | +$916,609 | +4.39% | |
| Ameriprise Financial Inc | 0.00% | 559,485 | $20,790,462 | $21,702,423 | +$911,961 | +4.39% | |
| Seven Grand Managers, Llc | 0.82% | 550,000 | $20,438,000 | $21,334,500 | +$896,500 | +4.39% | |
| Ghisallo Capital Management Llc | 0.36% | 500,000 | $18,580,000 | $19,395,000 | +$815,000 | +4.39% | |
| Clearstead Advisors, Llc | 0.17% | 473,937 | $17,611,499 | $18,384,016 | +$772,517 | +4.39% | |
| Royce & Associates Lp | 0.14% | 452,813 | $16,826,531 | $17,564,616 | +$738,085 | +4.39% | |
| Victory Capital Management Inc | 0.01% | 427,425 | $15,883,113 | $16,579,816 | +$696,703 | +4.39% | |
| Massachusetts Financial Services Co | 0.00% | 406,274 | $15,097,142 | $15,759,368 | +$662,226 | +4.39% | |
| Goldman Sachs Group Inc | 0.00% | 399,844 | $14,858,203 | $15,509,949 | +$651,746 | +4.39% | |
| Bnp Paribas Financial Markets | 0.01% | 394,688 | $14,666,606 | $15,309,948 | +$643,342 | +4.39% | |
| Charles Schwab Investment Management Inc | 0.00% | 373,541 | $13,880,784 | $14,489,655 | +$608,871 | +4.39% | |
| Allianz Asset Management Gmbh | 0.01% | 359,261 | $13,350,139 | $13,935,734 | +$585,595 | +4.39% | |
| D. E. Shaw & Co., Inc. | 0.01% | 355,528 | $13,211,421 | $13,790,931 | +$579,510 | +4.39% | |
| Tocqueville Asset Management L.P. | 0.17% | 338,225 | $12,568,441 | $13,119,748 | +$551,307 | +4.39% | |
| Vanguard Fiduciary Trust Co | 0.00% | 315,336 | $11,717,886 | $12,231,883 | +$513,997 | +4.39% | |
| Sei Investments Co | 0.01% | 307,062 | $11,410,378 | $11,910,935 | +$500,557 | +4.39% | |
| Assenagon Asset Management S.A. | 0.01% | 297,832 | $11,067,437 | $11,552,903 | +$485,466 | +4.39% | |
| Barclays Plc | 0.00% | 295,775 | $10,991,000 | $11,473,112 | +$482,112 | +4.39% | |
| Burkehill Global Management, Lp | 0.39% | 290,000 | $10,776,400 | $11,249,100 | +$472,700 | +4.39% | |
| Mad River Investors | 4.02% | 289,000 | $10,739,240 | $11,210,310 | +$471,070 | +4.39% |
Frequently asked questions about MIAX
Who owns the most MIAX stock?
The largest holders of MIAX are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX).
Is MIAX widely held by superinvestors?
Many widely followed stocks like MIAX appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly MIAX is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.