Insider Purchase: Murray Stahl/Horizon Kinetics Increase MIAX Stake; Options and Warrants Disclosed
Rhea-AI Filing Summary
Murray Stahl and Horizon Kinetics Asset Management LLC reported insider transactions in Miami International Holdings, Inc. (MIAX). On 08/28/2025 a Form 4 shows a purchase of 34,470 shares of MIAX common stock at $36.10 per share. After the reported transaction, the filing shows beneficial ownership of 4,557,919 shares held indirectly by Horizon Kinetics. The filing also lists several vested stock options held directly by Mr. Stahl (totaling 43,131 options across multiple grant exercise prices and expirations) and multiple vested warrants held indirectly by Horizon Kinetics (totaling 137,656 warrants across different strikes and expiration dates). The filing clarifies Mr. Stahls roles at Horizon Kinetics and disclaims direct beneficial ownership except for any pecuniary interest.
Positive
- Insider purchase of 34,470 shares at $36.10 on 08/28/2025 indicating additional economic exposure
- Substantial reported indirect ownership of 4,557,919 shares by Horizon Kinetics, showing significant stakeholder interest
- Multiple vested options and warrants are disclosed, clarifying potential future exercise activity and ownership changes
- Filing corrects prior omissions (shares inadvertently excluded from Form 3) and discloses conversions to common stock
Negative
- None.
Insights
TL;DR: Director and affiliated 10% owner reported a purchase and sizable indirect holdings, plus vested options and warrants.
The Form 4 documents a 34,470-share open-market purchase at $36.10 by or on behalf of accounts affiliated with Horizon Kinetics on 08/28/2025, increasing reported indirect beneficial ownership to 4,557,919 shares. The filing distinguishes between directly held, fully vested options in Mr. Stahls name and indirectly held warrants held by Horizon Kinetics. For investors, the combination of an outright purchase and substantial indirect stake signals continued economic exposure from the asset manager; the presence of multiple vested derivative instruments creates potential future share issuance if exercised. This disclosure is routine but material to ownership structure and dilution considerations.
TL;DR: Chairman/CEO of HKAM is reported as affiliated with a large indirect position and holds vested options; filing clarifies disclosure and disclaimers.
The filing provides clear role disclosure: Murray Stahl is Chairman, CEO, and CIO of Horizon Kinetics Asset Management LLC and the Form notes he does not exercise investment discretion for the managed accounts reported. The Form corrects prior omissions by including shares inadvertently excluded from an earlier Form 3 and identifies converted preferred and non-voting shares now reflected as common stock. The signature by an attorney-in-fact and the explanatory footnotes follow standard Section 16 protocols. This is a governance-appropriate, corrective and clarifying filing rather than an operational disclosure.
Insider Trade Summary
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Purchase | Common Stock | 34,470 | $36.10 | $1.24M |
| holding | OPTIONS | -- | -- | -- |
| holding | OPTIONS | -- | -- | -- |
| holding | OPTIONS | -- | -- | -- |
| holding | OPTIONS | -- | -- | -- |
| holding | Warrants | -- | -- | -- |
| holding | Warrants | -- | -- | -- |
| holding | Warrants | -- | -- | -- |
| holding | Warrants | -- | -- | -- |
Footnotes (5)
- F1. Murray Stahl serves as Chairman, Chief Executive Officer, and Chief Investment Officer of Horizon Kinetics Asset Management LLC ("HKAM"), which manages funds and accounts (the "Managed Accounts") that hold securities of the Issuer. Mr. Stahl does not exercise investment discretion with respect to the securities of the Issuer that are beneficially owned by the Managed Accounts. Mr. Stahl disclaims beneficial ownership over the securities reported, except to the extent of his pecuniary interest therein, if any. The filing of this Form shall not be deemed an admission that the Mr. Stahl is the beneficial owner of such securities for purposes of Section 16 or any other purpose.
- F2. Includes 5,000 shares of Series B Preferred Stock that have been converted into Common Stock on a one-for-one basis upon the closing of the Company's initial public offering and which have no expiration date and 14,998 shares of Non-Voting Common Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's IPO and which have no expiration date.
- F3. Includes Shares that were inadvertently excluded from the Form 3 filing made on August 13, 2025
- F4. The Options given to Mr. Stahl are fully vested.
- F5. The Warrants are currently vested and presently exercisable until the expiration date show.
AI-generated analysis. How Rhea-AI works. Not financial advice.
