Security key
59356Q108
MIAMI INTERNATIONAL HOLDINGS, INC. - COMMON STOCK (MIAX)
CUSIP: 59356Q108
Q3 2026 13F Holders as of 30 Sep 2026
- Security type / class
- Equity / COMMON STOCK
- Total 13F shares
- 373,508
- Total 13F value
- $12,511,813
- Share change
- -284,492
- SEC-reported price per share
- $33.50
- Number of holders
- 17
- Value change
- -$10,644,134
- Number of buys
- 8
- Number of sells
- 6
- Shares outstanding
- 94,961,698
Holder snapshot
6 signals
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q3 2026
Institutions
17
Top holders
10
MIAX full security history
Ownership snapshot
Full 13F holder table
MIAMI INTERNATIONAL HOLDINGS, INC. SEC filings
MIAMI INTERNATIONAL HOLDINGS, INC. company facts
Broader feeds
Reporting periods
Holder history for CUSIP 59356Q108
Recent filing periods:
Ownership snapshot
Top reported holders of MIAX - MIAMI INTERNATIONAL HOLDINGS, INC. - COMMON STOCK (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
HORIZON KINETICS ASSET MA...
Disclosed value leader
HORIZON KINETICS ASSET MA...
Comparable rows
4/15
Latest evidence
03 Sep 2026
13D/G
3/4/5
13F
Lead comparable stake: 7.8%
11 rows are not safely comparable across share classes.
13D/G row: HORIZON KINETICS ASSET MANAGEMENT LLC
Showing 1-6 of 15 holder rows.
Quick read
HORIZON KINETICS ASSET MANAGEMENT LLC leads the comparable SEC ownership view at 7.8%.
4 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens HORIZON KINETICS ASSET MANAGEMENT LLC's linked filing trail.
Comparable ownership
Top 4
HORIZON KINETICS ASSET MANAGEMENT...
7.8%
T. Rowe Price Investment Manageme...
5.3%
BlackRock, Inc.
5.1%
Thomas P. Gallagher
4.9%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-6 of 15 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| HORIZON KINETICS ASSET MANAGEMENT LLC |
13D/G
3/4/5
13F
10%+ Owner · Company
|
7.8%
Reported 13D/G
· 19 May 2026
|
$350,034,947
7,400,316 shares
|
-$177,965,919 | 19 May 2026 |
| T. Rowe Price Investment Management, Inc. |
13D/G
13F
Company
|
5.3%
Reported 13D/G
· 30 Jun 2026
|
$216,367,380
5,032,970 shares
|
$0 | 30 Jun 2026 |
| BlackRock, Inc. |
13F
13D/G
Company
|
5.1%
Reported 13D/G
· 30 Jun 2026
|
$188,466,378
5,071,754 shares
|
— | 30 Jun 2026 |
| Thomas P. Gallagher |
3/4/5
13D/G
Chairman & CEO, Director
|
4.9%
Reported 13D/G
· 26 Aug 2025
|
$89,617,458
2,643,920 shares
mixed-class rows
|
-$32,301,033 | 03 Sep 2026 |
| Murray Stahl |
3/4/5
Director
|
—
mixed-class rows
|
$199,625,913
4,675,269 shares
mixed-class rows
|
-$1,469,901 | 05 Mar 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13F
Company
|
—
denominator unverified
|
$140,703,293
3,786,418 shares
|
— | 30 Jun 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
13F holder rows
Institutional holders as of Q3 2026
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
17
Shares
373,508
Rows available
17
| Investor | Option | Weight % | Change % | SEC-reported value | * Price | Shares | Share Change | Activity | Report Period |
|---|
* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.
Compare Q3 2026 vs Q2 2026 Across Filers
Q2 2026 holders
205
Q3 2026 holders
17
Holder diff
-188
| Investor | Q2 2026 Shares | Q3 2026 Shares | Share Diff | Share Chg % | Q2 2026 value | Q3 2026 value | Value change | Value Chg % |
|---|
Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).
Quarterly Holders Trend
Quarterly Value Trend
Quarterly Shares Trend