Miami International Holdings MIAX Insider Ownership

NYSE MIAX

$31.53 +0.58 (+1.87%)

As of: Oct 19, 2026 · 3:59 PM EDT

Insider Holdings by Owner

11.64Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

10.87%

▼-0.385% pp QoQ

Shares Held by Insiders

10.72Mn

filed for Sep 2026

▼-3.42% QoQ

Shares Outstanding

98.61Mn

98,610,560 shares

Direct Holdings

3.33Mn

Indirect: 7.39Mn

Net Shares Traded (QoQ)

-379.70K

net selling in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 10, 2026

In the last 12 months, insiders at Miami International Holdings made open-market purchases of $722,511 (16.84K shares) and open-market sales of $81.51 million (1.91Mn shares).

Counted by insider, open-market buying of MIAX stock in the past 12 months came from one insider and selling from 11 insiders.
Among Miami International Holdings' insiders, Murray Stahl (Director) was the largest open-market buyer over the past 12 months, purchasing $722,511 of stock (16.84K shares), most recently on March 5, 2026.
Conversely, Thomas P. Gallagher (Chairman & CEO) was MIAX's largest open-market seller in the past 12 months, with $32.3 million of sales (749.06K shares); the latest was on September 3, 2026.
The newest open-market trade among Miami International Holdings insiders came on October 2, 2026, when Douglas M. Schafer Jr. (EVP and CIO) made a sale of 40K shares for $1.33 million.
Outside the open market, Miami International Holdings insiders received 363.19K shares in stock awards, acquired 1.77Mn shares through option exercises and conversions, gave up 509.17K shares to cover taxes or exercise prices and gave away 2K shares as gifts over the past 12 months.
Per Business Quant data, Miami International Holdings insiders hold 10.72Mn shares in total based on their latest Form 4 filings, down 3.42% from 11.1Mn shares at the end of Q2 2026 and down 19.41% from 13.3Mn shares at the end of Q3 2025.
Indirect holdings, through trusts, partnerships, family members and other entities, make up 68.90% (7.39Mn shares) of Miami International Holdings' insider total, with the other 31.10% (3.33Mn shares) held directly.
The insider holdings in Miami International Holdings belong to 25 insiders who have reported on Form 4 within the past two years.
Miami International Holdings' top three insider holders by shares held are Talal Jassim Al-Bahar (Director, 3.66Mn shares), Thomas P. Gallagher (Chairman & CEO, 2.21Mn shares) and Horizon Kinetics Asset Management LLC (10% owner, 2.17Mn shares).
The holding of Talal Jassim Al-Bahar makes up 34.12% of all shares held by Miami International Holdings insiders.
Institutions accounted for 72.77% of MIAX's outstanding shares in Q2 2026, insiders about 10.87% per their latest Form 4 filings, and other investors, including the public, about 16.36%.
In the last 12 months, 114 Form 4 filings with transactions in MIAX stock came from 25 insiders.
These insider figures for Miami International Holdings are based on Form 4 filings through October 6, 2026.

Form 4 Holdings

Insiders Holding MIAX

Insiders 26

Shares held 11.64Mn

Of outstanding 11.81%

#	Insider	Position	Direct	Indirect	Total	Share of Insiders	Last Filed
1	Murray Stahl	Director	0	4,633,842	4,633,842	39.8%	06 Mar, 2026
2	Thomas P. Gallagher	Chairman Ceo	786,542	1,423,275	2,209,817	19.0%	04 Sep, 2026
3	Kinetics Asset Management Llc Horizon	TenPercentOwner	0	2,170,898	2,170,898	18.6%	21 May, 2026
4	Barbara J. Comly	Evp, Gc Corporate Secretary	839,564	0	839,564	7.2%	04 Sep, 2026
5	Douglas M. Jr Schafer	Evp And Cio	387,414	0	387,414	3.3%	06 Oct, 2026
6	Shelly Brown	Evp, Chief Strategy Officer	316,490	0	316,490	2.7%	17 Sep, 2026
7	John Smollen	Evp, New Product Development	178,212	0	178,212	1.5%	18 Jun, 2026
8	Judson Gray Teekell	Director	69,251	81,000	150,251	1.3%	04 Sep, 2026
9	Kurt M. Eckert	Director	149,612	0	149,612	1.3%	06 Aug, 2026
10	Edward Deitzel	Evp, Cro, Cco Miax Exchanges	119,601	0	119,601	1.0%	04 Sep, 2026
11	Cynthia Schwarzkopf	Director	88,545	0	88,545	0.8%	19 Aug, 2026
12	Lance Emmons	Evp And Cfo	86,538	0	86,538	0.7%	19 Aug, 2026
13	Harish Jayabalan	Evp, Ciso And Cro	86,398	0	86,398	0.7%	29 Sep, 2026
14	Mark F. Raymond	Director	67,064	0	67,064	0.6%	17 Jun, 2026
15	Paul Stahlin	Director	42,143	0	42,143	0.4%	17 Jun, 2026
16	Talal Jassim Al-Bahar	Director	40,891	0	40,891	0.4%	17 Jun, 2026
17	John Beckelman	Director	15,904	0	15,904	0.1%	17 Jun, 2026
18	Lisa Moore	Director	12,737	0	12,737	0.1%	17 Jun, 2026
19	Mark I. Massad	Director	10,737	0	10,737	0.1%	17 Jun, 2026
20	Kenneth W. Lozier	Director	8,237	0	8,237	0.1%	17 Jun, 2026
21	David A Brown	Director	7,066	0	7,066	0.1%	09 Jul, 2026
22	Jill E. Sommers	Director	6,083	0	6,083	0.1%	17 Jun, 2026
23	Eric Sites	Director	5,684	0	5,684	0.0%	17 Jun, 2026
24	Cees Vermaas	Ceo Of Tiseg	4,660	0	4,660	0.0%	18 Jun, 2026
25	Jamil Nazarali	Director	2,500	0	2,500	0.0%	15 Aug, 2025
26	Lee Becker	Director	2,267	0	2,267	0.0%	17 Jun, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

650 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
02 Oct, 2026	Douglas M. Jr Schafer	Evp And Cio	Acquired M	40,000	$12.00	$480.00K	427,414	Direct
02 Oct, 2026	Douglas M. Jr Schafer	Evp And Cio	Disposed S	40,000	$33.34	$1.33Mn	387,414	Direct
02 Oct, 2026	Douglas M. Jr Schafer	Evp And Cio	Disposed M	40,000	$0.00	$0	155,334	Direct
25 Sep, 2026	Harish Jayabalan	Evp, Ciso And Cro	Acquired M	8,333	$12.00	$100.00K	86,398	Direct
25 Sep, 2026	Harish Jayabalan	Evp, Ciso And Cro	Disposed M	8,333	$0.00	$0	8,333	Direct
16 Sep, 2026	Shelly Brown	Evp, Chief Strategy Officer	Disposed S	21,217	$38.61	$819.19K	316,490	Direct
11 Sep, 2026	Shelly Brown	Evp, Chief Strategy Officer	Disposed F	16,283	$42.54	$692.68K	337,707	Direct
03 Sep, 2026	Edward Deitzel	Evp, Cro, Cco Miax Exchanges	Acquired M	11,000	$12.00	$132.00K	130,601	Direct
02 Sep, 2026	Douglas M. Jr Schafer	Evp And Cio	Acquired M	43,334	$12.00	$520.01K	430,748	Direct
03 Sep, 2026	Thomas P. Gallagher	Chairman Ceo	Acquired M	47,000	$12.00	$564.00K	1,470,275	Indirect
02 Sep, 2026	Judson Gray Teekell	Director	Disposed S	5,545	$41.58	$230.56K	81,000	Indirect
02 Sep, 2026	Barbara J. Comly	Evp, Gc Corporate Secretary	Acquired M	44,445	$12.00	$533.34K	884,009	Direct
02 Sep, 2026	Douglas M. Jr Schafer	Evp And Cio	Acquired M	4,666	$12.00	$55.99K	435,414	Direct
03 Sep, 2026	Thomas P. Gallagher	Chairman Ceo	Disposed S	47,000	$42.43	$1.99Mn	1,423,275	Indirect
02 Sep, 2026	Barbara J. Comly	Evp, Gc Corporate Secretary	Disposed S	44,445	$40.49	$1.80Mn	839,564	Direct
02 Sep, 2026	Judson Gray Teekell	Director	Disposed S	3,000	$40.89	$122.67K	69,251	Direct
03 Sep, 2026	Edward Deitzel	Evp, Cro, Cco Miax Exchanges	Disposed S	11,000	$42.21	$464.31K	119,601	Direct
02 Sep, 2026	Barbara J. Comly	Evp, Gc Corporate Secretary	Disposed M	44,445	$0.00	$0	44,444	Direct
02 Sep, 2026	Douglas M. Jr Schafer	Evp And Cio	Disposed S	48,000	$40.48	$1.94Mn	387,414	Direct
03 Sep, 2026	Edward Deitzel	Evp, Cro, Cco Miax Exchanges	Disposed M	11,000	$0.00	$0	66,000	Direct

Showing 1 to 20 of 650 transactions