MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) Insider Trading
Over the last 3 months, MIAX insiders made 0 open-market buys and 33 sales, a net sale of -$38.2M (SEC Form 4). Over the last 6 months, 175 institutions increased and 77 reduced their position (13F).
Insider Activity
Sentiment
0/100
Buys (3m)
0
Sells (3m)
33
Net (3m)
-$38.2M
Insider trades by month Buys Sells
Mar
Apr
May
Jun
Jul
Aug
Context3-month price -7.4%Institutions accumulating (13F)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Aug 20, 2026 | Comly Barbara J.officer: EVP, GC & Corporate Secretary | Tax | 43,420 | $42.41 |
| Aug 20, 2026 | Gallagher Thomas P.director, officer: Chairman & CEO | Sell | 149,700 | $41.13 |
| Aug 20, 2026 | Gallagher Thomas P.director, officer: Chairman & CEO | Tax | 150,300 | $42.41 |
| Aug 19, 2026 | Emmons Lanceofficer: EVP and CFO | Sell | 35,000 | $42.83 |
| Aug 19, 2026 | Schwarzkopf Cynthiadirector | Sell | 5,000 | $42.85 |
| Aug 19, 2026 | Schwarzkopf Cynthiadirector | Option | 5,000 | $12.00 |
| Aug 6, 2026 | Deitzel Edwardofficer: EVP, CRO, CCO MIAX Exchanges | Option | 11,000 | $12.00 |
| Aug 6, 2026 | Comly Barbara J.officer: EVP, GC & Corporate Secretary | Sell | 44,445 | $45.69 |
| Aug 6, 2026 | Jayabalan Harishofficer: EVP, CISO and CRO | Sell | 20,000 | $45.90 |
| Aug 6, 2026 | Jayabalan Harishofficer: EVP, CISO and CRO | Option | 5,832 | $15.22 |
| Aug 6, 2026 | Jayabalan Harishofficer: EVP, CISO and CRO | Option | 14,168 | $12.00 |
| Aug 6, 2026 | Teekell Judson Graydirector | Sell | 3,000 | $45.79 |
| Aug 6, 2026 | Eckert Kurt M.director | Sell | 1,063 | $45.80 |
| Aug 6, 2026 | Comly Barbara J.officer: EVP, GC & Corporate Secretary | Option | 44,445 | $12.00 |
| Aug 6, 2026 | Gallagher Thomas P.director, officer: Chairman & CEO | Sell | 48,334 | $45.69 |
| Aug 6, 2026 | Gallagher Thomas P.director, officer: Chairman & CEO | Option | 48,334 | $12.00 |
| Aug 6, 2026 | Schafer Douglas M. JRofficer: EVP and CIO | Sell | 48,000 | $45.71 |
| Aug 6, 2026 | Schafer Douglas M. JRofficer: EVP and CIO | Option | 48,000 | $12.00 |
| Aug 6, 2026 | Deitzel Edwardofficer: EVP, CRO, CCO MIAX Exchanges | Sell | 11,000 | $45.78 |
| Aug 6, 2026 | Eckert Kurt M.director | Option | 1,063 | $12.00 |
| Jul 16, 2026 | Schwarzkopf Cynthiadirector | Option | 5,000 | $12.00 |
| Jul 16, 2026 | Schwarzkopf Cynthiadirector | Sell | 5,000 | $42.00 |
| Jul 14, 2026 | Gallagher Thomas P.director, officer: Chairman & CEO | Option | 70,000 | $12.00 |
| Jul 14, 2026 | Comly Barbara J.officer: EVP, GC & Corporate Secretary | Option | 28,000 | $12.00 |
| Jul 14, 2026 | Comly Barbara J.officer: EVP, GC & Corporate Secretary | Sell | 28,000 | $41.98 |
| Jul 14, 2026 | Gallagher Thomas P.director, officer: Chairman & CEO | Sell | 70,000 | $42.52 |
| Jul 9, 2026 | BROWN DAVID Adirector | Tax | 171 | $43.72 |
| Jul 7, 2026 | Gallagher Thomas P.director, officer: Chairman & CEO | Sell | 41,772 | $42.09 |
| Jul 7, 2026 | Schafer Douglas M. JRofficer: EVP and CIO | Sell | 48,000 | $41.22 |
| Jul 7, 2026 | Schafer Douglas M. JRofficer: EVP and CIO | Option | 42,000 | $12.00 |
Source: MIAX SEC Form 4 filings, latest Aug 20, 2026. For informational purposes only — not investment advice.
Institutional activity (13F)
How institutions changed their MIAX positions over the last 6 months (SEC Form 13F).
Increased
175
New positions
133
Reduced
77
Sold out
39
Largest moves
| Institution | Action | Shares | Filed |
|---|---|---|---|
| HORIZON KINETICS ASSET MANAGEMENT LLC | Increased | 7.8M | Aug 11, 2026 |
| BlackRock, Inc. | Increased | 5.1M | Aug 7, 2026 |
| T. Rowe Price Investment Management, Inc. | Increased | 5.0M | Aug 14, 2026 |
| T. ROWE PRICE INVESTMENT MANAGEMENT, INC. | Increased | 4.1M | May 15, 2026 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Increased | 3.8M | Aug 14, 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Increased | 3.8M | Aug 13, 2026 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Increased | 3.6M | May 15, 2026 |
| HORIZON KINETICS ASSET MANAGEMENT LLC | Increased | 3.5M | May 15, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | Increased | 3.2M | Aug 13, 2026 |
| BLACKROCK, INC. | Increased | 2.2M | May 13, 2026 |
| Invesco Ltd. | Increased | 2.0M | Aug 14, 2026 |
| J Digital 6 LLC | New Position | 1.8M | Aug 13, 2026 |
| BLAIR WILLIAM & CO/IL | Increased | 1.8M | Aug 11, 2026 |
| CITADEL ADVISORS LLC | Increased | 1.7M | May 15, 2026 |
| BALYASNY ASSET MANAGEMENT L.P. | New Position | 1.7M | Aug 14, 2026 |
Source: SEC Form 13F filings. For informational purposes only — not investment advice.