Miami International Holdings
MIAX
206 hedge funds and large institutions have $2.68B invested in Miami International Holdings in 2026 Q2 according to their latest regulatory filings, with 48 funds opening new positions, 93 increasing their positions, 46 reducing their positions, and 41 closing their positions.
102% more repeat investments, than reductions
Existing positions increased: 93 | Existing positions reduced: 46
50% more funds holding in top 10
Funds holding in top 10: 4 → 6 (+2)
38% more capital invested
Capital invested by funds: $1.95B → $2.68B (+$732M)
21.17% more ownership
Funds ownership: 54.82% → 75.98% (+21%)
17% more first-time investments, than exits
New positions opened: 48 | Existing positions closed: 41
15% more call options, than puts
Call options by funds: $27.6M | Put options by funds: $24M
2% more funds holding
Funds holding: 202 → 206 (+4)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
HKAM
Horizon Kinetics Asset Management
New York
|
+$196M |
| 2 |
BlackRock
New York
|
+$127M |
| 3 |
Vanguard Portfolio Management
Malvern,
Pennsylvania
|
+$108M |
| 4 |
JD6
J Digital 6
Chicago,
Illinois
|
+$80.8M |
| 5 |
Vanguard Capital Management
Malvern,
Pennsylvania
|
+$78.3M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Citadel Advisors
Miami,
Florida
|
-$71.9M |
| 2 |
NRCM
North Reef Capital Management
Laguna Beach,
California
|
-$34.1M |
| 3 |
Alyeska Investment Group
Chicago,
Illinois
|
-$26.8M |
| 4 |
GCM
Ghisallo Capital Management
Boston,
Massachusetts
|
-$22.4M |
| 5 |
Millennium Management
New York
|
-$14.7M |
MIAX Hedge Fund Activity: Q2 2026 in Review
206 of the 8,329 institutional investors tracked by Wall St. Rank reported a position in Miami International Holdings (MIAX) for Q2 2026, worth a combined $2.68B — up 38% from $1.95B a quarter earlier.
Buyers outnumbered sellers: 48 funds opened new MIAX positions and 41 closed out — a net gain of 7 holders — while 93 added to existing stakes and 46 trimmed.
The largest buyer was Horizon Kinetics Asset Management, adding an estimated $196M. The largest seller was Citadel Advisors, exiting entirely with an estimated $71.9M sold.
- 206 institutional investors held Miami International Holdings (MIAX) as of Q2 2026, up from 202 in Q1 2026.
- Funds reported $2.68B of Miami International Holdings stock for Q2 2026, up 38% quarter-over-quarter.
- 48 funds opened new Miami International Holdings positions in Q2 2026 and 41 closed out, a net change of +7 holders.
- The largest Miami International Holdings buyer in Q2 2026 was Horizon Kinetics Asset Management, an estimated $196M added.
- The largest Miami International Holdings seller in Q2 2026 was Citadel Advisors, an estimated $71.9M sold.
Based on aggregated 13F filings for Q2 2026.