STOCK TITAN

Insider at Miami International Holdings (MIAX) exercises options, sells 48K

(Neutral)
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Miami International Holdings EVP and CIO Douglas M. Schafer Jr exercised 48,000 nonqualified stock options at $12.0000 per share into 48,000 shares of common stock, then sold 48,000 shares at a weighted average price of $45.7100 per share pursuant to a previously established Rule 10b5-1 Plan adopted on December 16, 2025. The options were fully vested, and he continues to hold 43,334 stock options following this exercise.

Positive

  • None.

Negative

  • None.
Insider Schafer Douglas M. JR
Role EVP and CIO
Sold 48,000 shs ($2.19M)
Approx. gross sale proceeds $2.19M
Approx. exercise cost $576K
Approx. pre-tax spread $1.62M
Type Security Shares Price Value
Exercise Nonqualified Stock Option (Right to Buy) F1, F3 48,000 $0.00 $0.00
Exercise Common Stock F1 48,000 $12.00 $576K
Sale Common Stock F1, F2 48,000 $45.71 $2.19M
Holdings After Transaction: Nonqualified Stock Option (Right to Buy) — 43,334 shares (Direct); Common Stock — 387,414 shares (Direct)
Footnotes (3)
  1. F1. This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 16, 2025.
  2. F2. This transaction was executed in multiple trades throughout the day at prices ranging from $45.09 to $46.78. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
  3. F3. The options are fully vested.
Options exercised 48000.0000 shares Nonqualified stock options exercised by EVP and CIO on 2026-08-04
Option exercise price $12.0000 per share Exercise price for Nonqualified Stock Option (Right to Buy)
Shares sold 48000.0000 shares Common stock sold by the reporting person on 2026-08-04
Weighted average sale price $45.7100 per share Weighted average price for shares sold in multiple trades between $45.09 and $46.78
Sale price range $45.09–$46.78 per share Range of individual trade prices for the 48,000 shares sold
Options remaining 43334.0000 shares Nonqualified stock options held following the reported exercise
10b5-1 plan adoption date December 16, 2025 Date the reporting person adopted the Rule 10b5-1 Plan governing these trades
Rule 10b5-1 Plan regulatory
"This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted"
A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.
Nonqualified Stock Option financial
"security title "Nonqualified Stock Option (Right to Buy)""
weighted average sales price financial
"The price reported above reflects the weighted average sales price"
derivative security financial
"transaction code description "Exercise or conversion of derivative security""
A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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FAQ

What insider transaction did MIAX executive Douglas M. Schafer Jr report?

Douglas M. Schafer Jr reported exercising 48,000 nonqualified stock options at $12.0000 and receiving 48,000 common shares, followed by selling 48,000 shares at a weighted average price of $45.7100 per share on August 4, 2026.

At what prices did the MIAX insider exercise options and sell shares?

Schafer exercised options at $12.0000 per share and sold 48,000 common shares at a weighted average price of $45.7100 per share, with individual trade prices ranging from $45.09 to $46.78 during the day.

Was the MIAX Form 4 transaction by Douglas Schafer under a Rule 10b5-1 plan?

Yes. The filing states the trades were effected pursuant to a previously established Rule 10b5-1 Plan adopted by the reporting person on December 16, 2025, indicating the transactions followed a pre-arranged trading schedule.

How many MIAX stock options does Douglas Schafer hold after this Form 4?

After exercising 48,000 options, Schafer is reported to hold 43,334 nonqualified stock options. The filing notes these options are fully vested, giving him the right to buy additional shares before their May 17, 2028 expiration.

What is the nature of the MIAX securities involved in Douglas Schafer’s Form 4?

The transactions involve Nonqualified Stock Options (Right to Buy) with an exercise price of $12.0000 per share, converting into common stock, and a subsequent sale of 48,000 shares of common stock at a weighted average of $45.7100 per share.
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Schafer Douglas M. JR

(Last)(First)(Middle)
C/O MIAMI INTERNATIONAL HOLDINGS, INC.
7 ROSZEL ROAD, SUITE 1A

(Street)
PRINCETON NEW JERSEY 08540

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
MIAMI INTERNATIONAL HOLDINGS, INC. [ MIAX ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
EVP and CIO
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
08/04/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock08/04/2026M(1)48,000A$12435,414D
Common Stock08/04/2026S(1)48,000D$45.71(2)387,414D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Nonqualified Stock Option (Right to Buy)$1208/04/2026M(1)48,000 (3)05/17/2028Common Stock48,000$043,334D
Explanation of Responses:
1. This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 16, 2025.
2. This transaction was executed in multiple trades throughout the day at prices ranging from $45.09 to $46.78. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
3. The options are fully vested.
Remarks:
/s/ Alessandra Henriques Corona, Attorney-in-fact08/06/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)