MIAMI INTL HLDGS INC MIAX
COM · Common Stock · CUSIP 59356Q108
Holdings company for MIAX exchanges and other entities
- SectorFinancials
- IndustrySecurity Brokers, Dealers & Flotation Companies
- HeadquartersPrinceton, NJ
- Websitemiaxoptions.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($8.8k this quarter). Holder counts are more reliable. Shares outstanding: 94.9m as of 2026-04-30, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $38.92. Options: 6 managers hold calls ($13.4m notional), 6 hold puts ($11.0m).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2025 | 116 |
| Q4 2025 | 162 |
| Q1 2026 | 203 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q4 2025 | 125 | 42 |
| Q1 2026 | 158 | 60 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $0 | $0 | — |
| Q3 2025 | $11.5m | $7.3m | 0.63 |
| Q4 2025 | $6.4m | $3.5m | 0.55 |
| Q1 2026 | $13.4m | $11.0m | 0.82 |
Biggest buyers
| HORIZON KINETICS ASSET MANAGEMENT LLC | Added | +1.6m |
| CITADEL ADVISORS LLC | Added | +988.2k |
| MORGAN STANLEY | Added | +926.1k |
| TWO SIGMA INVESTMENTS, LP | Added | +753.4k |
| T. Rowe Price Investment Management, Inc. | Added | +609.9k |
| BANK OF AMERICA CORP /DE/ | Added | +597.0k |
| Clearstead Advisors, LLC | New | +503.7k |
| BlackRock, Inc. | Added | +479.2k |
| Ghisallo Capital Management LLC | Added | +442.5k |
| JPMORGAN CHASE & CO | Added | +423.7k |
Biggest sellers
| JANE STREET GROUP, LLC | Sold out | -638.0k |
| Jump Financial, LLC | Reduced | -266.3k |
| North Reef Capital Management LP | Reduced | -250.7k |
| AMERICAN CENTURY COMPANIES INC | Reduced | -226.8k |
| Monashee Investment Management LLC | Sold out | -175.0k |
| Lykos Global Management, LP | Sold out | -175.0k |
| WELLINGTON MANAGEMENT GROUP LLP | Reduced | -171.3k |
| GOLDMAN SACHS GROUP INC | Reduced | -154.4k |
| Driehaus Capital Management LLC | Reduced | -135.7k |
| Unisphere Establishment | Sold out | -135.0k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $9.2m237.3k shares |
| CITADEL ADVISORS LLC | Unchanged | $1.5m38.9k shares |
| JANE STREET GROUP, LLC | New | $1.1m28.7k shares |
| SIG BROKERAGE, LP | New | $778.4k20.0k shares |
| IMC-Chicago, LLC | Added | $677.2k17.4k shares |
| SIMPLEX TRADING, LLC | Added | $101.2k2.6k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $3.2m82.0k shares |
| CITADEL ADVISORS LLC | Added | $1.8m46.8k shares |
| SIMPLEX TRADING, LLC | Added | $1.7m43.8k shares |
| SIG BROKERAGE, LP | New | $1.6m40.0k shares |
| JANE STREET GROUP, LLC | Added | $1.5m38.2k shares |
| IMC-Chicago, LLC | New | $1.3m33.0k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
HORIZON KINETICS ASSET MANAGEMENT LLC
13D · may seek influence
-4.4 pts · filed 2026-05-21
Stated purposeHKAM acquired the securities reported herein on behalf of the Managed Accounts for investment purposes. In the ordinary course of its business, HKAM intends to regularly review its equity interest in the Issuer and may, from time to time, acquire additional shares or other securities of the Issuer. While HKAM has no present intention to dispose of all or any portion of the shares beneficially owned by Managed Accounts, it may sell shares from time to time for a number of reasons, not limited to client requests, regulatory or investment limitations or other reasons. Any such sales of securities of the Issuer may be in the open market, privately negotiated transactions or otherwise. On May 19, 2026, HKAM distributed 4,084,261 shares in-kind on a pro rata basis without consideration to the b… Full filing |
7.8% |
| BlackRock, Inc. 13G · institution +1.1 pts · filed 2026-10-27 | 6.2% |
| T. Rowe Price Investment Management, Inc. 13G · institution new · filed 2026-08-14 | 5.3% |
Insider purchases and sales in Q1 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q2 2024 | 0 | — | 0 | — | — |
| Q3 2024 | 0 | — | 0 | — | — |
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 11 | $2.0m | 0 | — | — |
| Q4 2025 | 1 | $100.1k | 0 | — | — |
| Q1 2026 | 1 | $622.5k | 5 | $6.6m | $4.4m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-25 | Teekell Judson Gray Director | Sold | $12.0k300 shares |
| 2026-03-23 | Brown Shelly EVP, Chief Strategy Officer | Sold plan | $1.0m25.9k shares |
| 2026-03-19 | Eckert Kurt M. Director | Sold plan | $1.5m37.9k shares |
| 2026-03-17 | Schafer Douglas M. JR EVP and CIO | Sold plan | $1.9m48.0k shares |
| 2026-03-05 | STAHL MURRAY +1 Director · Horizon Kinetics Asset Management LLC | Bought | $310.2k7.2k shares |
| 2026-03-04 | STAHL MURRAY +1 Director · Horizon Kinetics Asset Management LLC | Bought | $312.3k7.2k shares |
| 2026-03-02 | STAHL MURRAY +1 Director · Horizon Kinetics Asset Management LLC | Sold | $2.2m53.6k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| T. Rowe Price Investment Management, Inc. 0.11% of their portfolio | 4.1m $161.3m | Added +609.9k |
| HORIZON KINETICS ASSET MANAGEMENT LLC 1.46% of their portfolio | 3.5m $134.3m | Added +1.6m |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.17% of their portfolio | 3.3m $128.3m | Added +11.4k |
| BlackRock, Inc. 0.00% of their portfolio | 2.2m $86.9m | Added +479.2k |
| CITADEL ADVISORS LLC 0.04% of their portfolio | 1.6m $62.6m | Added +988.2k |
| Invesco Ltd. 0.01% of their portfolio | 1.6m $61.7m | Added +306.0k |
| Alyeska Investment Group, L.P. 0.16% of their portfolio | 1.4m $56.3m | Added +161.4k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 1.4m $55.1m | First filing |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 1.4m $53.5m | First filing |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.07% of their portfolio | 1.2m $48.5m | Added +365.7k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 1.2m $46.4m | Added +423.7k |
| AMERICAN CENTURY COMPANIES INC 0.02% of their portfolio | 1.2m $47.5m | Reduced -226.8k |
| MORGAN STANLEY 0.00% of their portfolio | 1.1m $44.6m | Added +926.1k |
| Allspring Global Investments Holdings, LLC 0.07% of their portfolio | 1.1m $43.8m | Added +180.2k |
| North Reef Capital Management LP 1.36% of their portfolio | 1.0m $39.5m | Reduced -250.7k |
| Ghisallo Capital Management LLC 1.07% of their portfolio | 1.0m $38.9m | Added +442.5k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 900.9k $35.1m | Added +597.0k |
| TWO SIGMA INVESTMENTS, LP 0.03% of their portfolio | 893.7k $34.8m | Added +753.4k |
| LORD, ABBETT & CO. LLC 0.11% of their portfolio | 860.7k $33.5m | Added +201.0k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 779.8k $30.4m | Added +267.0k |
| STATE STREET CORP 0.00% of their portfolio | 712.3k $27.7m | Added +135.9k |
| BLAIR WILLIAM & CO/IL 0.07% of their portfolio | 665.8k $25.9m | Added +10.9k |
| Caldwell Investment Management Ltd. 9.77% of their portfolio | 663.8k $24.9m | Reduced -75.0k |
| BNP PARIBAS FINANCIAL MARKETS 0.01% of their portfolio | 572.5k $22.3m | Added +381.4k |
| FRANKLIN RESOURCES INC 0.01% of their portfolio | 568.2k $22.1m | Added +141.0k |
| SEVEN GRAND MANAGERS, LLC 1.43% of their portfolio | 550.0k $21.4m | Added +150.0k |
| SEI INVESTMENTS CO 0.02% of their portfolio | 526.4k $20.5m | Added +186.1k |
| MILLENNIUM MANAGEMENT LLC 0.02% of their portfolio | 518.7k $20.2m | Added +234.0k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 509.5k $19.8m | Added +61.9k |
| Clearstead Advisors, LLC 0.18% of their portfolio | 503.7k $19.6m | New |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 444.9k $17.3m | Reduced -171.3k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 426.3k $16.6m | Reduced -154.4k |
| UBS Group AG 0.00% of their portfolio | 423.4k $16.5m | Added +260.5k |
| Driehaus Capital Management LLC 0.11% of their portfolio | 396.7k $15.4m | Reduced -135.7k |
| VICTORY CAPITAL MANAGEMENT INC 0.01% of their portfolio | 389.6k $15.2m | Reduced -2.6k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.00% of their portfolio | 341.3k $13.3m | Added +67.4k |
| D. E. Shaw & Co., Inc. 0.01% of their portfolio | 320.8k $12.5m | New |
| TOCQUEVILLE ASSET MANAGEMENT L.P. 0.18% of their portfolio | 312.1k $12.1m | Added +91.4k |
| ROYCE & ASSOCIATES LP 0.12% of their portfolio | 309.3k $12.0m | Added +127.8k |
| Burkehill Global Management, LP 0.56% of their portfolio | 290.0k $11.3m | Unchanged |
| Delta Global Management LP 0.92% of their portfolio | 287.7k $11.2m | Added +8.6k |
| INTRINSIC EDGE CAPITAL MANAGEMENT LLC 1.96% of their portfolio | 276.0k $10.7m | Reduced -46.5k |
| BARCLAYS PLC 0.00% of their portfolio | 274.2k $10.7m | Added +217.1k |
| Penn Capital Management Company, LLC 0.83% of their portfolio | 273.8k $10.7m | Added +21.7k |
| RENAISSANCE TECHNOLOGIES LLC 0.02% of their portfolio | 271.5k $10.6m | Added +76.4k |
| Woodline Partners LP 0.04% of their portfolio | 261.1k $10.2m | Unchanged |
| TUDOR INVESTMENT CORP ET AL 0.05% of their portfolio | 259.8k $10.1m | Added +203.8k |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND 0.02% of their portfolio | 240.0k $9.3m | Added +5.8k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 237.3k $9.2m | Added +50.2k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 234.0k $9.1m | Added +64.4k |
| Nuveen, LLC 0.00% of their portfolio | 231.9k $9.0m | Added +192.8k |
| Trexquant Investment LP 0.06% of their portfolio | 215.5k $8.4m | New |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 202.6k $7.9m | First filing |
| FEDERATED HERMES, INC. 0.01% of their portfolio | 201.1k $7.8m | Added +1.1k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.01% of their portfolio | 179.0k $7.0m | Added +16.8k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.01% of their portfolio | 164.0k $6.4m | Added +17.0k |
| AXIOM INVESTORS LLC /DE 0.07% of their portfolio | 163.3k $6.4m | Reduced -79.9k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 159.2k $6.2m | Added +28.7k |
| Schonfeld Strategic Advisors LLC 0.05% of their portfolio | 157.7k $6.1m | Added +57.7k |
| Optiver Holding B.V. 0.22% of their portfolio | 152.6k $5.9m | Added +311 |
| OCCUDO QUANTITATIVE STRATEGIES LP 0.38% of their portfolio | 151.7k $7.1m | New |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.00% of their portfolio | 149.9k $5.8m | New |
| SOROS FUND MANAGEMENT LLC 0.07% of their portfolio | 132.6k $5.2m | Reduced -22.0k |
| Portolan Capital Management, LLC 0.27% of their portfolio | 128.8k $5.0m | New |
| Prana Capital Management, LP 0.15% of their portfolio | 123.4k $4.8m | Added +106.2k |
| MARSHALL WACE, LLP 0.01% of their portfolio | 122.6k $4.8m | New |
| Aquatic Capital Management LLC 0.13% of their portfolio | 119.5k $4.7m | New |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 119.4k $4.6m | Added +17.0k |
| Polar Capital Holdings Plc 0.02% of their portfolio | 118.7k $4.6m | Reduced -5.3k |
| TRUIST FINANCIAL CORP 0.01% of their portfolio | 117.8k $4.6m | New |
| KING LUTHER CAPITAL MANAGEMENT CORP 0.02% of their portfolio | 117.3k $4.6m | Added +13.5k |
| TD Asset Management Inc 0.00% of their portfolio | 106.0k $4.1m | Added +25.5k |
| CITIGROUP INC 0.00% of their portfolio | 105.4k $4.1m | Added +93.5k |
| Caprock Group, LLC 0.10% of their portfolio | 100.6k $3.9m | Added +90.6k |
| Quantbot Technologies LP 0.15% of their portfolio | 96.0k $3.7m | New |
| MBL Wealth, LLC 0.26% of their portfolio | 87.0k $3.4m | New |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.01% of their portfolio | 85.6k $3.3m | New |
| Qube Research & Technologies Ltd 0.00% of their portfolio | 82.5k $3.2m | New |
| MAD RIVER INVESTORS 1.14% of their portfolio | 81.2k $3.2m | Added +6.2k |
| WEXFORD CAPITAL LP 0.52% of their portfolio | 80.4k $3.1m | New |
| Coastal Bridge Advisors, LLC 0.22% of their portfolio | 78.0k $3.0m | Added +601 |
| Bank of New York Mellon Corp 0.00% of their portfolio | 78.0k $3.0m | Added +17.6k |
| SPIREPOINT PRIVATE CLIENT, LLC 0.25% of their portfolio | 68.9k $2.7m | New |
| Bullseye Asset Management LLC 1.49% of their portfolio | 65.9k $2.6m | Added +39.2k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 61.2k $2.4m | Added +25.6k |
| one8zero8, LLC 0.51% of their portfolio | 59.1k $2.3m | Added +650 |
| Quantinno Capital Management LP 0.00% of their portfolio | 55.5k $2.2m | New |
| G2 Investment Partners Management LLC 0.50% of their portfolio | 52.6k $2.0m | New |
| Engineers Gate Manager LP 0.03% of their portfolio | 51.7k $2.0m | New |
| Corient Private Wealth LP 0.00% of their portfolio | 51.4k $2.0m | New |
| CREDIT AGRICOLE S A 0.01% of their portfolio | 51.0k $2.0m | Unchanged |
| Atlas Brown,Inc. 0.60% of their portfolio | 51.0k $2.0m | New |
| Covalis Capital LLP 0.12% of their portfolio | 50.0k $1.9m | Added +10.0k |
| C2P Capital Advisory Group, LLC d.b.a. Prosperity Capital Advisors 0.10% of their portfolio | 46.9k $1.8m | New |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 44.9k $1.7m | Added +4.7k |
| Squarepoint Ops LLC 0.00% of their portfolio | 40.2k $1.6m | New |
| Entropy Technologies, LP 0.07% of their portfolio | 40.1k $1.6m | New |
| LPL Financial LLC 0.00% of their portfolio | 39.9k $1.6m | New |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 39.3k $1.5m | Reduced -3.2k |
| NewEdge Advisors, LLC 0.01% of their portfolio | 39.0k $1.5m | New |