Miami International Holdings
MIAX
161 hedge funds and large institutions have $1.66B invested in Miami International Holdings in 2025 Q4 according to their latest regulatory filings, with 69 funds opening new positions, 62 increasing their positions, 20 reducing their positions, and 23 closing their positions.
210% more repeat investments, than reductions
Existing positions increased: 62 | Existing positions reduced: 20
200% more first-time investments, than exits
New positions opened: 69 | Existing positions closed: 23
83% more call options, than puts
Call options by funds: $6.44M | Put options by funds: $3.52M
61% more capital invested
Capital invested by funds: $1.03B → $1.66B (+$631M)
46.03% more ownership
Funds ownership: 0% → 46.03% (+46%)
40% more funds holding
Funds holding: 115 → 161 (+46)
33% more funds holding in top 10
Funds holding in top 10: 3 → 4 (+1)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
American Century Companies
Kansas City,
Missouri
|
+$53.2M |
| 2 |
BlackRock
New York
|
+$46.6M |
| 3 |
Invesco
Atlanta,
Georgia
|
+$36.6M |
| 4 |
T. Rowe Price Investment Management
Baltimore,
Maryland
|
+$26.5M |
| 5 |
Vanguard Group
Malvern,
Pennsylvania
|
+$24.3M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Citadel Advisors
Miami,
Florida
|
-$15.9M |
| 2 |
Morgan Stanley
New York
|
-$13.4M |
| 3 |
T. Rowe Price Associates
Baltimore,
Maryland
|
-$12M |
| 4 |
Royal Bank of Canada
Toronto,
Ontario, Canada
|
-$8.85M |
| 5 |
GC
Gillson Capital
Chicago,
Illinois
|
-$8.33M |
MIAX Hedge Fund Activity: Q4 2025 in Review
161 of the 8,270 institutional investors tracked by Wall St. Rank reported a position in Miami International Holdings (MIAX) for Q4 2025, worth a combined $1.66B — up 61% from $1.03B a quarter earlier.
Buyers outnumbered sellers: 69 funds opened new MIAX positions and 23 closed out — a net gain of 46 holders — while 62 added to existing stakes and 20 trimmed.
The largest buyer was American Century Companies, adding an estimated $53.2M. The largest seller was Citadel Advisors, cutting an estimated $15.9M.
- 161 institutional investors held Miami International Holdings (MIAX) as of Q4 2025, up from 115 in Q3 2025.
- Funds reported $1.66B of Miami International Holdings stock for Q4 2025, up 61% quarter-over-quarter.
- 69 funds opened new Miami International Holdings positions in Q4 2025 and 23 closed out, a net change of +46 holders.
- The largest Miami International Holdings buyer in Q4 2025 was American Century Companies, an estimated $53.2M added.
- The largest Miami International Holdings seller in Q4 2025 was Citadel Advisors, an estimated $15.9M sold.
Based on aggregated 13F filings for Q4 2025.