How many institutional investors hold MIAX?

3 tracked institutional investors disclosed a position in MIAX (MIAMI INTL HLDGS INC) in their most recent 13F filing.

Who is the largest institutional holder of MIAX?

Ken Griffin, Citadel Advisors, holds the largest disclosed position in MIAX, valued at $66M.

Where does this MIAX ownership data come from?

SEC Form 13F-HR filings, accessed via EDGAR. 13F filings are disclosed quarterly with a 45-day reporting delay and cover U.S.-listed long equity positions only. This is not investment advice.

MIAX — MIAMI INTL HLDGS INC

Name: MIAMI INTL HLDGS INC (MIAX) — Institutional Ownership
Creator: InvestorLens
License: https://www.sec.gov/about/website-policies

Public company

For educational research only.InvestorLens analyzes public regulatory filings (SEC EDGAR, STOCK Act PTRs) that may be delayed by 45 days or more. Information shown is historical and is not financial, legal, or tax advice, nor a recommendation or solicitation to buy or sell any security. Always do your own research.

InvestorLens aggregates public filing data to show which tracked investors reported holdings in this stock. Dollar values represent reported position values, not market capitalization, and may be delayed up to 45 days. Not a recommendation.

Sourced from SEC EDGAR public filings

About MIAMI INTL HLDGS INC (MIAX)

MIAMI INTL HLDGS INC (MIAX) appears in the most recent 13F filings of 3 tracked institutional investors. The largest disclosed position is held by Ken Griffin (Citadel Advisors), valued at $66M. Across recent filings, tracked investors recorded 2 new positions, 0 increased, 0 reduced, and 0 exited. All data sourced from SEC 13F filings.

Tracked investors reporting MIAX

Investor	Firm	Shares	Market value	% of portfolio	As of
Ken Griffin	Citadel Advisors	1.7M	$65.9M	0.01%	Mar 31, 2026
Izzy Englander	Millennium Management	518.7K	$20.2M	0.01%	Mar 31, 2026
George Soros	Soros Fund Management	132.6K	$5.2M	0.06%	Mar 31, 2026

Ken GriffinMar 31, 2026
Citadel Advisors
Shares
1.7M
Value
$65.9M
% Portfolio
0.01%
Izzy EnglanderMar 31, 2026
Millennium Management
Shares
518.7K
Value
$20.2M
% Portfolio
0.01%
George SorosMar 31, 2026
Soros Fund Management
Shares
132.6K
Value
$5.2M
% Portfolio
0.06%

Recent activity

Investor	Action	Δ %	Current value	Filing date
George Soros	New	—	$6.9M	Feb 13, 2026
George Soros	New	—	$5.2M	May 15, 2026

George Soros
New
$6.9MFeb 13, 2026
George Soros
New
$5.2MMay 15, 2026

Frequently asked questions

How many institutional investors hold MIAX?: 3 tracked institutional investors disclosed a position in MIAX (MIAMI INTL HLDGS INC) in their most recent 13F filing.
Who is the largest institutional holder of MIAX?: Ken Griffin, Citadel Advisors, holds the largest disclosed position in MIAX, valued at $66M.
Did institutional ownership of MIAX increase or decrease?: Across recent 13F filings, tracked investors recorded 2 new positions, 0 increased, 0 reduced, and 0 fully exited MIAX.
Where does this MIAX ownership data come from?: SEC Form 13F-HR filings, accessed via EDGAR. 13F filings are disclosed quarterly with a 45-day reporting delay and cover U.S.-listed long equity positions only. This is not investment advice.