GALLAGHER THOMAS P. (Chairman & CEO) sold 3.2% of their position (47K shares) of MIAMI INTERNATIONAL HOLDINGS, INC. on the open market

Open‑market sale worth $1.99M — a minor trim. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 1 sale

GALLAGHER THOMAS P.

Filed: 9/4/2026ACC: 0002080477-26-000018

InsiderGALLAGHER THOMAS P.CIK 2080477

→

IssuerMIAMI INTERNATIONAL HOLDINGS, INC.CIK 1438472

DirectorOfficer· Chairman & CEO

Since Feb 2026

-47K

Net shares

Net seller

$1.99M

Total sold

Open market trades

0B · 1S

Total transactions

89.60K acquired · 136.60K disposed

Non-Derivative Transactions6

Common Stock

Indirect

M · Option Exercise

+47K

Price / share

$12.00

Trade value

$564K

% of position

3.3%

9/3/2026

1.42M→1.47M

Common Stock

Indirect

S · Sale

−47K

Price / share

$42.43

Trade value

$1.99M

% of position

3.2%

9/3/2026

1.47M→1.42M

Common Stock

Direct

M · Option Exercise

+16.67K

Price / share

$12.00

Trade value

$199.99K

% of position

2.2%

9/3/2026

743.94K→760.61K

Common Stock

Direct

M · Option Exercise

+8.33K

Price / share

$12.00

Trade value

$100K

% of position

1.1%

9/3/2026

760.61K→768.94K

Common Stock

Direct

M · Option Exercise

+13.14K

Price / share

$15.22

Trade value

$199.99K

% of position

1.7%

9/3/2026

768.94K→782.08K

Common Stock

Direct

M · Option Exercise

+4.46K

Price / share

$22.40

Trade value

$99.99K

% of position

0.6%

9/3/2026

782.08K→786.54K

Total

Net shares

+42.60K

Net value

-$830.24K

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Common Stock Indirect	9/3/2026	M · Option Exercise	+47K	$12.00	$564K	3.3%	1.42M	1.47M
Common Stock Indirect	9/3/2026	S · Sale	−47K	$42.43	$1.99M	3.2%	1.47M	1.42M
Common Stock Direct	9/3/2026	M · Option Exercise	+16.67K	$12.00	$199.99K	2.2%	743.94K	760.61K
Common Stock Direct	9/3/2026	M · Option Exercise	+8.33K	$12.00	$100K	1.1%	760.61K	768.94K
Common Stock Direct	9/3/2026	M · Option Exercise	+13.14K	$15.22	$199.99K	1.7%	768.94K	782.08K
Common Stock Direct	9/3/2026	M · Option Exercise	+4.46K	$22.40	$99.99K	0.6%	782.08K	786.54K
Total			+42.60K		-$830.24K

Derivative Transactions5

Nonqualified Stock Option (Right to Buy)

Indirect

M · Option Exercise

Converts to

Common Stock

47K shares

−47K

Strike price

Held after

188K

Exercisable

—

9/3/2026

Incentive Stock Option (Right to Buy)

Direct

M · Option Exercise

Converts to

Common Stock

16.67K shares

−16.67K

Strike price

Held after

0.00

Exercisable

—

9/3/2026

Incentive Stock Option (Right to Buy)

Direct

M · Option Exercise

Converts to

Common Stock

8.33K shares

−8.33K

Strike price

Held after

0.00

Exercisable

—

9/3/2026

Incentive Stock Option (Right to Buy)

Direct

M · Option Exercise

Converts to

Common Stock

13.14K shares

−13.14K

Strike price

15.22

Held after

0.00

Exercisable

—

9/3/2026

Incentive Stock Option (Right to Buy)

Direct

M · Option Exercise

Converts to

Common Stock

4.46K shares

−4.46K

Strike price

22.40

Held after

8.93K

Exercisable

—

9/3/2026

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Nonqualified Stock Option (Right to Buy) Indirect	Common Stock47K shares	9/3/2026	M · Option Exercise	−47K	12	—	188K
Incentive Stock Option (Right to Buy) Direct	Common Stock16.67K shares	9/3/2026	M · Option Exercise	−16.67K	12	—	0.00
Incentive Stock Option (Right to Buy) Direct	Common Stock8.33K shares	9/3/2026	M · Option Exercise	−8.33K	12	—	0.00
Incentive Stock Option (Right to Buy) Direct	Common Stock13.14K shares	9/3/2026	M · Option Exercise	−13.14K	15.22	—	0.00
Incentive Stock Option (Right to Buy) Direct	Common Stock4.46K shares	9/3/2026	M · Option Exercise	−4.46K	22.40	—	8.93K