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

Why are billionaires buying MIAX?

Built from public SEC filings and public economic data. Not a recommendation.

Confidence

Institutional Conviction

Strong distribution · 0 buying vs 1 selling last quarter

Macro Tailwind

Macro conditions are mixed for this sector

Why? — Evidence & Confidence ▾

Of 1 tracked investors who changed their MIAX position last quarter, 0 bought and 1 sold (0% buy-side). Macro conditions are mixed for this sector (Macro Tailwind 55/100 in a Contraction regime).

Supporting evidence

+3 tracked investors reported holding MIAX at their latest filing
+Macro Health is 55/100 in a Contraction regime — historically acceptable for this sectorsource

Contradicting evidence — always shown

−1 tracked investor reduced or exited last quarter (0 reduced, 1 sold out)
−13F data is disclosed up to 45 days after quarter end — positions may have changed since

Know the limits

· 13F disclosure lag (up to 45 days)
· Tracked investors are a sample, not the whole market
· Sector regime fit is a historical average, not a guarantee

Every InvestorLens score shows its evidence — including what argues against it. Model conviction-v1 · generated 9/17/2026.

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 1 new positions, 1 increased, 1 reduced, and 1 exited. All data sourced from SEC 13F filings.

Smart Money Consensus™

Based on recent institutional activity in MIAX

/100

Mixed Activity

Added / Increased2

Reduced1

Exited1

BearishBullish

Crowded Trade Score™

How many top investors track MIAX

/100

Emerging Interest

3investors

A small number of top investors own this.

UndiscoveredCrowded

151015+

MIAX Ownership Composition

How MIAMI INTL HLDGS INC is held across tracked investor types, based on reported 13F positions.

Dominant Type

Multi-Strategy / Quant

99% of tracked value

Institutions

tracked investors

Total Reported

$13.9M

combined 13F value

Multi-Strategy / Quant98.5%
Macro1.5%

Multi-Strategy / Quant(2)

98.5%

Macro(1)

1.5%

Tracked investors currently reporting MIAX

1 tracked investor has since exited this position — listed separately below.

Investor	Firm	Shares	Market value	% of portfolio	As of
Ken Griffin	Citadel Advisors	179.3K	$6.7M	0.00%	Jun 30, 2026
Izzy Englander	Millennium Management	189.1K	$7M	0.00%	Jun 30, 2026
Paul Tudor Jones	Tudor Investment Corp	5.5K	$204.4K	0.00%	Jun 30, 2026

Ken GriffinJun 30, 2026
Citadel Advisors
Shares
179.3K
Value
$6.7M
% Portfolio
0.00%
Izzy EnglanderJun 30, 2026
Millennium Management
Shares
189.1K
Value
$7M
% Portfolio
0.00%
Paul Tudor JonesJun 30, 2026
Tudor Investment Corp
Shares
5.5K
Value
$204.4K
% Portfolio
0.00%

Previously held MIAX

These investors reported MIAX in an earlier quarter but not in their most recent 13F. Figures below are their last reported position, not a current holding.

Investor	Firm	Last reported shares	Value then	Last held
George Soros	Soros Fund Management	132.6K	$5.2M	Mar 31, 2026

Recent activity

Investor	Action	Δ %	Current value	Filing date
George Soros	New	—	$4.2M	Nov 14, 2025
George Soros	Increased	48.24%	$6.9M	Feb 13, 2026
George Soros	Reduced	-14.21%	$5.2M	May 15, 2026
George Soros	Sold	-100.00%	$0	Aug 14, 2026

George Soros
New
$4.2MNov 14, 2025
George Soros
Increased
$6.9M(48.24%)Feb 13, 2026
George Soros
Reduced
$5.2M(-14.21%)May 15, 2026
George Soros
Sold
$0(-100.00%)Aug 14, 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 1 new positions, 1 increased, 1 reduced, and 1 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.