Miami International Holdings
MIAX
118 hedge funds and large institutions have $1.03B invested in Miami International Holdings in 2025 Q3 according to their latest regulatory filings, with 118 funds opening new positions, increasing their positions, reducing their positions, and closing their positions.
58% more call options, than puts
Call options by funds: $11.5M | Put options by funds: $7.25M
31.24% more ownership
Funds ownership: 0% → 31.24% (+31%)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Susquehanna International Group
Bala Cynwyd,
Pennsylvania
|
+$120M |
| 2 |
T. Rowe Price Investment Management
Baltimore,
Maryland
|
+$88.9M |
| 3 |
Vanguard Group
Malvern,
Pennsylvania
|
+$50.6M |
| 4 |
Horizon Kinetics Asset Management
New York
|
+$50.6M |
| 5 |
Alyeska Investment Group
Chicago,
Illinois
|
+$46.3M |
Top Sellers
MIAX Hedge Fund Activity: Q3 2025 in Review
118 of the 7,659 institutional investors tracked by Wall St. Rank reported a position in Miami International Holdings (MIAX) for Q3 2025, worth a combined $1.03B.
Buyers outnumbered sellers: 118 funds opened new MIAX positions and 0 closed out — a net gain of 118 holders — while 0 added to existing stakes and 0 trimmed.
The largest buyer was Susquehanna International Group, opening a new position worth an estimated $120M.
- 118 institutional investors held Miami International Holdings (MIAX) as of Q3 2025, up from 0 in Q2 2025.
- Funds reported $1.03B of Miami International Holdings stock for Q3 2025.
- 118 funds opened new Miami International Holdings positions in Q3 2025 and 0 closed out, a net change of +118 holders.
- The largest Miami International Holdings buyer in Q3 2025 was Susquehanna International Group, an estimated $120M added.
Based on aggregated 13F filings for Q3 2025.