Security Snapshot

MIAMI INTERNATIONAL HOLDINGS, INC. - Common Stock (MIAX) Institutional Ownership

CUSIP: 59356Q108

13F Institutional Holders and Ownership History from Q3 2025 to Q3 2026

13F reference period

Q2 2026

Institutions Reporting

206

Shares (Excl. Options)

72.11MFull value: 72,114,523 · shares · 30 Jun 2026

Price

$37.16

The headline uses the Q2 2026 reference period after its reporting deadline. Available reports may still be incomplete or amended. Newer periods in the history table contain incoming reports and may be incomplete.

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Latest holder snapshot 5 signals
Portfolio coverage rank
0.01%
Share change
+22,073,249
Value change
+$810,878,034
Number of holders
206
Issuer context Names, identifiers, and filing context for this profile. 3 identity fields
Shares outstanding
98,784,129
SEC-reported price per share
$30.70
Insider filing price
$30.70
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Filing notes and source

Key facts

  • MIAX - MIAMI INTERNATIONAL HOLDINGS, INC. - Common Stock is tracked under CUSIP 59356Q108.
  • 206 institutions reported positions in Q2 2026.
  • 4 significant owners is listed from Schedule 13D/13G reporting.

Change

  • Holder count moved from 199 to 206 between Q1 2026 and Q2 2026.
  • SEC-reported value moved from
    $1.95BFull value: $1,948,044,705 · USD · 31 Mar 2026
    to
    $2.68BFull value: $2,681,366,922 · USD · 30 Jun 2026
    .

Research use

  • You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
  • 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.

Evidence

Source: SEC Form 13F

Latest holder context comes from 206 institutions filings for Q2 2026.

Open SEC evidence

Security key

59356Q108

13F reference period

Q2 2026

13F holders

206

13D/G owners

4

CIK / CUSIP context first

13D/G owners

Significant owners

Large-stake holder rows connected to Schedule 13D/G evidence.

Rows
4
Security
MIAX
Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
HORIZON KINETICS ASSET MANAGEMENT LLC 7.8% -37% $350,034,947 -$177,965,919 7,400,316 -34% HORIZON KINETICS ASSET MANAGEMENT LLC 19 May 2026
BlackRock, Inc. 6.2% +22% $205,174,636 +$39,349,971 6,124,616 +24% BlackRock, Inc. 30 Sep 2026
T. Rowe Price Investment Management, Inc. 5.3% $216,367,380 5,032,970 T. Rowe Price Investment Management, Inc. 30 Jun 2026
Gallagher Thomas P. 4.9% -4% 4,036,237 -4.5% Thomas P. Gallagher 26 Aug 2025
As of 30 Jun 2026, 206 institutional investors reported holding
72.11MFull value: 72,114,523 · shares · 30 Jun 2026
shares of MIAMI INTERNATIONAL HOLDINGS, INC. - Common Stock (MIAX). This represents 73% of the company’s total
98.78MFull value: 98,784,129 · shares · Stored outstanding share count
outstanding shares.

13F concentration

Top 25 institutional shareholders

Largest 13F positions for this security by reported shares and value.

Top holder share
52%
Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
HORIZON KINETICS ASSET MANAGEMENT LLC 7.9% 7,842,173 +127% 3.3% $291,415,166
BlackRock, Inc. 5.1% 5,071,754 +127% 0% $188,466,378
T. Rowe Price Investment Management, Inc. 5.1% 5,032,970 +21% 0.12% $187,026,000
VANGUARD PORTFOLIO MANAGEMENT LLC 3.8% 3,786,418 +175% 0.01% $140,703,293
SUSQUEHANNA INTERNATIONAL GROUP, LLP 3.4% 3,355,043 +1.8% 0.11% $124,673,398
VANGUARD CAPITAL MANAGEMENT LLC 3.2% 3,165,686 +124% 0% $117,636,892
Invesco Ltd. 2% 2,020,650 +27% 0.01% $75,087,354
J Digital 6 LLC 1.8% 1,807,234 40% $67,156,815
BLAIR WILLIAM & CO/IL 1.8% 1,769,432 +166% 0.17% $65,752,093
Balyasny Asset Management L.P. 1.7% 1,682,924 0.11% $62,537,456
AMERICAN CENTURY COMPANIES INC 1.6% 1,587,196 +30% 0.03% $58,980,261
STATE STREET CORP 1.5% 1,432,894 +101% 0% $53,246,341
JPMORGAN CHASE & CO 1.4% 1,427,881 +15% 0% $52,718,389
GEODE CAPITAL MANAGEMENT, LLC 1.4% 1,395,680 +79% 0% $51,869,678
ADAGE CAPITAL PARTNERS GP, L.L.C. 1.2% 1,143,920 -8.3% 0.06% $42,508,067
HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND 1.1% 1,039,449 +333% 0.06% $38,625,925
LORD, ABBETT & CO. LLC 1% 1,000,866 +16% 0.11% $37,192,000
MORGAN STANLEY 0.96% 950,593 -17% 0% $35,324,037
TWO SIGMA INVESTMENTS, LP 0.9% 888,109 -0.63% 0.02% $33,002,130
Allspring Global Investments Holdings, LLC 0.87% 857,682 -23% 0.05% $33,492,482
BANK OF AMERICA CORP /DE/ 0.87% 856,980 -4.9% 0% $31,845,377
Alyeska Investment Group, L.P. 0.86% 848,750 -41% 0.08% $31,539,550
PRICE T ROWE ASSOCIATES INC /MD/ 0.85% 844,464 +430% 0% $31,381,000
FRANKLIN RESOURCES INC 0.79% 784,799 +38% 0.01% $29,163,130
Walleye Capital LLC 0.74% 728,034 +1790% 0.13% $27,053,743

Quarter history

Institutional holders across reporting periods

Holder count, reported shares/value, and median price by quarter.

Periods
5
Headline period
Q2 2026
Rows shown
1-5 of 5
Period 13F Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2026 Q3 6,667,859 $222,998,053 +$31,454,073 $33.50 60
2026 Q2 72,114,523 $2,681,366,922 +$810,878,034 $37.16 206
2026 Q1 50,070,919 $1,948,044,705 +$428,606,917 $38.92 199
2025 Q4 37,336,537 $1,657,285,443 +$508,570,468 $44.38 160
2025 Q3 25,501,338 $1,026,412,421 +$1,026,412,421 $40.26 114
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