Miami International Holdings, Inc. (MIAX) Ownership
MIAX ownership summary
as of October 18, 2026- Institutions
- 74.5% of shares outstanding
- Insiders
- 9.67% of shares outstanding
- Shares outstanding
- 99.2M
- Float
- 93.3M shares available to trade
- Short interest
- 11.26% 8.9M shares short
- Days to cover
- 5.27 short interest up 30.8% vs prior month
- Institutions 74.49%
- Insiders 9.67%
- Other investors 15.84%
MIAX top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Horizon Asset Management Inc/ny | 7.90% | 7.8M | $242.7M | +4.4M (+127.2%) | June 30, 2026 |
| 2 | BlackRock Inc | 5.11% | 5.1M | $157.0M | +2.8M (+127.2%) | June 30, 2026 |
| 3 | T. Rowe Price Investment Management,Inc. | 5.07% | 5.0M | $155.8M | +887,352 (+21.4%) | June 30, 2026 |
| 4 | Vanguard Portfolio Management, LLC | 3.82% | 3.8M | $117.2M | +2.4M (+175.4%) | June 30, 2026 |
| 5 | Susquehanna International Group, LLP | 3.38% | 3.4M | $103.8M | +58,697 (+1.8%) | June 30, 2026 |
| 6 | Vanguard Capital Management, LLC | 3.19% | 3.2M | $98.0M | +1.8M (+123.7%) | June 30, 2026 |
| 7 | Amvescap Plc. | 2.04% | 2.0M | $62.5M | +435,647 (+27.5%) | June 30, 2026 |
| 8 | J Digital 6 LLC | 1.82% | 1.8M | $55.9M | +1.8M (0.0%) | June 30, 2026 |
| 9 | Blair William & Co | 1.78% | 1.8M | $54.8M | +1.1M (+165.8%) | June 30, 2026 |
| 10 | Balyasny Asset Management LLC | 1.70% | 1.7M | $52.1M | +1.7M (0.0%) | June 30, 2026 |
| 11 | American Century Companies Inc | 1.60% | 1.6M | $49.1M | +365,711 (+29.9%) | June 30, 2026 |
| 12 | State Street Corp | 1.44% | 1.4M | $44.3M | +720,565 (+101.2%) | June 30, 2026 |
| 13 | JPMorgan Chase & Co | 1.44% | 1.4M | $44.2M | +189,875 (+15.3%) | June 30, 2026 |
| 14 | Geode Capital Management, LLC | 1.41% | 1.4M | $43.2M | +615,898 (+79.0%) | June 30, 2026 |
| 15 | Adage Capital Partners Gp LLC | 1.15% | 1.1M | $35.4M | −103,079 (−8.3%) | June 30, 2026 |
| 16 | HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 1.05% | 1.0M | $32.2M | +799,449 (+333.1%) | June 30, 2026 |
| 17 | Lord, Abbett & Co LLC | 1.01% | 1.0M | $31.0M | +140,179 (+16.3%) | June 30, 2026 |
| 18 | Morgan Stanley - Brokerage Accounts | 0.96% | 951K | $29.4M | −196,363 (−17.1%) | June 30, 2026 |
| 19 | Two Sigma Investments LLC | 0.90% | 888K | $27.5M | −5,609 (−0.6%) | June 30, 2026 |
| 20 | Allspring Global Investments Holdings, LLC | 0.86% | 858K | $26.5M | −254,579 (−22.9%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 16 holders added 20.2M shares and 4 cut 560K.
MIAX top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 2.74% | 2.7M | $84.1M | −3,268 (−0.1%) | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 2.06% | 2.0M | $63.4M | −1,864 (−0.1%) | September 30, 2026 |
| 3 | Vanguard Small Cap Index | 1.98% | 2.0M | $60.8M | +2,018 (+0.1%) | August 31, 2026 |
| 4 | T. Rowe Price Small-Cap Stock | 1.53% | 1.5M | $46.9M | +55,188 (+3.8%) | August 31, 2026 |
| 5 | Vanguard MStar Small Cap Value Index | 1.26% | 1.2M | $38.6M | +966 (+0.1%) | August 31, 2026 |
| 6 | Horizon Kinetics Inflation Bnfcrs ETF | 0.98% | 972K | $30.1M | +2,400 (+0.2%) | September 30, 2026 |
| 7 | American Century Small Cap Growth Inv | 0.98% | 970K | $30.0M | +239,646 (+32.8%) | June 30, 2026 |
| 8 | Franklin Small Cap Growth Adv | 0.85% | 848K | $26.3M | — | August 31, 2026 |
| 9 | Fidelity Small Cap Index | 0.84% | 836K | $25.9M | +7,119 (+0.9%) | July 31, 2026 |
| 10 | T. Rowe Price Instl Small-Cap Stock | 0.83% | 826K | $25.6M | +47,069 (+6.0%) | August 31, 2026 |
| 11 | iShares Russell 2000 Growth ETF | 0.74% | 735K | $22.8M | −931 (−0.1%) | September 30, 2026 |
| 12 | JPMorgan Small Cap Equity A | 0.71% | 704K | $21.8M | +11,945 (+1.7%) | August 31, 2026 |
| 13 | T. Rowe Price Small-Cap Value | 0.70% | 695K | $21.5M | −6,369 (−0.9%) | August 31, 2026 |
| 14 | Invesco Main Street Small Cap R6 | 0.55% | 549K | $17.0M | — | August 31, 2026 |
| 15 | Schwab US Small-Cap ETF™ | 0.47% | 470K | $14.5M | +315 (+0.1%) | September 30, 2026 |
| 16 | Vanguard Russell 2000 ETF | 0.44% | 440K | $13.6M | +10,426 (+2.4%) | August 31, 2026 |
| 17 | Lord Abbett Developing Growth A | 0.43% | 426K | $13.2M | −130,912 (−23.5%) | July 31, 2026 |
| 18 | Invesco Small Cap Growth A | 0.41% | 405K | $12.5M | — | August 31, 2026 |
| 19 | Kinetics Paradigm No Load | 0.39% | 387K | $12.0M | +341,422 (+748.7%) | June 30, 2026 |
| 20 | Strategic Advisers U.S. Total Stock | 0.39% | 382K | $11.8M | +112,249 (+41.6%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
MIAX insider transactions
latest 18| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-15 | Thomas P Gallagher | Sell | $43.68 | 49,900 | $2.2M |
| 2026-04-15 | Thomas P Gallagher | Sell | $43.36 | 174,125 | $7.6M |
| 2026-04-15 | Barbara J Comly | Sell | $43.64 | 29,667 | $1.3M |
| 2026-04-08 | Edward Deitzel | Sell | $42.02 | 7,572 | $318,175 |
| 2026-04-08 | Shelly Brown | Sell | $42.08 | 16,434 | $691,543 |
| 2026-04-07 | Edward Deitzel | Sell | $42.00 | 4,763 | $200,046 |
| 2026-04-07 | Shelly Brown | Sell | $42.00 | 900 | $37,800 |
| 2026-04-06 | Shelly Brown | Sell | $41.33 | 2,357 | $97,415 |
| 2026-04-02 | Judson Gray Teekell | Sell | $40.00 | 2,700 | $108,000 |
| 2026-03-23 | Shelly Brown | Sell | $39.33 | 25,932 | $1.0M |
| 2026-03-20 | Gilbert Ray Cisneros, Jr. | Buy | $39.17 | — | — |
| 2026-03-19 | Kurt M Eckert | Sell | $39.00 | 37,917 | $1.5M |
| 2026-03-17 | Douglas M Schafer Jr | Sell | $39.74 | 48,000 | $1.9M |
| 2026-03-04 | Murray Stahl | Buy | $43.38 | 7,200 | $312,336 |
| 2026-03-02 | Murray Stahl | Sell | $40.92 | 121,054 | $5.0M |
| 2025-10-03 | Murray Stahl | Buy | $41.97 | 2 | $84 |
| 2025-09-26 | Murray Stahl | Buy | $41.76 | 4 | $167 |
| 2025-08-28 | Murray Stahl | Buy | $36.10 | 34,470 | $1.2M |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
MIAX shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns MIAX
Institutional investors own 74.5% of Miami International's shares and insiders 9.67%. The largest holder is Horizon Asset Management Inc/ny with 7.90% of the shares (7.8M), as of June 30, 2026. Among the top 20 institutions, 16 added shares and 4 reduced their stake in the latest filings. Short interest is 11.26% of the float, or 5.27 days of average trading volume. The share count fell 12.1% since 2023.
Related: MIAX analyst forecast, MIAX key metrics. See the MIAX stock overview for the latest quote and news.
MIAX ownership FAQ
Who owns the most Miami International stock?
The largest shareholders of Miami International are Horizon Asset Management Inc/ny (7.90%), BlackRock Inc (5.11%), T. Rowe Price Investment Management,Inc. (5.07%), Vanguard Portfolio Management, LLC (3.82%), Susquehanna International Group, LLP (3.38%).
What percentage of Miami International is owned by institutions?
Institutions hold 74.5% of Miami International's shares outstanding; insiders hold 9.67%.
Which funds own Miami International?
The largest fund holders of Miami International are Vanguard MStar Total Stk Mkt Idx Invest (2.74%), iShares Russell 2000 ETF (2.06%), Vanguard Small Cap Index (1.98%), T. Rowe Price Small-Cap Stock (1.53%), Vanguard MStar Small Cap Value Index (1.26%).
What is Miami International's short interest?
8.9M shares of Miami International were sold short, 11.26% of the float; at the average daily volume it would take 5.27 days to cover.
Are insiders buying or selling Miami International?
Of the latest 18 reported insider transactions in Miami International (since August 28, 2025), 5 were purchases and 13 were sales.
How many shares of Miami International are outstanding?
Miami International has 99.2M shares outstanding, of which 93.3M are in the public float.