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Institutional Cluster

MIAX

MIAMI INTERNATIONAL HOLDINGS, INC.
NEUTRAL
Impact 3/10
Horizonweeks Processed4mo ago
Institutional cluster: 4 buyers, 1 sellers (bullish)
Actionable Insight • Neutral

The cluster is dominated by passive rebalancing, not active conviction. Monitor for any subsequent 13F filings or activist 13D to confirm a catalyst. The 45-day lag means the buying may have already been reversed — check recent price action for signs of distribution.

DirectionNeutral
Confidencemedium
Horizonweeks
Final — all horizons settled through T+60d ⚠ clustered
MIAX ▲ +2.71% at T+60d
NEUTRAL call +2.71% · α vs SPY -1.68% · entry $41.27 → $42.39
Entry = T+0 close
Jun 11, 2026
via day close
T+1d
+4.89%
call +4.89% · α +4.35%
$43.29
settled 5mo ago
T+5d
-8.41%
call -8.41% · α -8.84%
$37.80
settled 4mo ago
T+20d
+4.17%
call +4.17% · α +2.28%
$42.99
settled 4mo ago
T+60d
+2.71%
call +2.71% · α -1.68%
$42.39
settled 7w ago

Executive Summary

Four mega-passive institutional investors (Vanguard, BlackRock, State Street, Fidelity) collectively added $102.6M in MIAX shares during Q4 2025, while Morgan Stanley trimmed $11.2M. The buying is dominated by index-fund rebalancing, not active manager conviction, and the 45-day disclosure lag means positions may have already been adjusted. The cluster signals passive accumulation but lacks the active-manager catalyst that typically drives outsized returns.

Key Financial Metrics

Direction
accumulating
Buy Value
$189.0M
Sell Value
$21.0M
Net Flow
$102.6M

Institutional Positions

Net institutional flow: $102.6M

▲ Buyers (4)

InstitutionActionChangePosition ValueValue Δ
VanguardADD+39.5%$85.6M$29.9M
BlackRockDOUBLED+147.8%$77.8M$49.3M
State StreetDOUBLED+921.1%$25.6M$23.3M
FidelityDOUBLED+1866.7%$65.0K$62.0K

▼ Sellers (1)

InstitutionActionChangePrev ValueValue Δ
Morgan StanleyTRIM-57.6%$21.0M-$11.2M

Key Facts

  • 4 mega-passive buyers added $102.6M net; 1 seller reduced by $11.2M
  • BlackRock doubled its position (+147.8%) to $77.8M; State Street added 921.1% to $25.6M
  • All buyers are passive/index-fund managers — no active hedge fund or activist involvement
  • Morgan Stanley trimmed 57.6% of its position, selling $11.2M
  • 13F data reflects Q4 2025 quarter-end positions, filed with ~45-day lag

Financial Impact

Net institutional accumulation of $102.6M across 4 buyers, offset by $11.2M in selling from Morgan Stanley

institutional ownershipfloat

Risk Factors

  • Passive buying may be index-driven and not reflect fundamental thesis
  • 45-day disclosure lag: positions may have been unwound since quarter-end
  • Morgan Stanley's trim could signal institutional rotation ahead of known headwinds

Market Snapshot

Exchange
NYSE
Sector
Security Brokers, Dealers & Flotation Companies
Analyst Consensus
67% bullish (12 analysts)

Investment Themes

Traditional Finance

Documents Analyzed

This report is based on 1 institutional 13F filing from SEC EDGAR.

DocumentAccession Number
INST-CLUSTER Data (Synthetic)inst-cluster-MIAX-2025-Q4
41 reports for MIAX
Performance horizon
67% Hit rate @ T+1 6 of 9 directional calls Went positive at some point 9 of 9 best @ T+5▲ +10.93%May 6, 2026
Filters
Rows
Reports for MIAX — sortable, filterable
TypeNow
Oct 1, 2026
25d ago
Press Release
NEUTRAL ★ 1/10
$33.75 $33.01▼ −2.19%▼ −2.93%—
Sep 4, 2026
7w ago
Insider Cluster
NEUTRAL ★ 3/10
$43.46 $42.89▼ −1.31%▼ −0.85%—
Sep 4, 2026
7w ago
Insider Cluster
NEUTRAL ★ 2/10
$43.46 $42.89▼ −1.31%▼ −0.85%—
Aug 19, 2026
9w ago
Insider Cluster
MIXED ★ 5/10
$41.32 $42.59▲ +3.07%▲ +2.66%—
Aug 19, 2026
9w ago
Insider Cluster
BEARISH ★ 5/10
$41.32 $42.59▼ −3.07%▼ −2.66%—
Aug 6, 2026
11w ago
Insider Cluster
BEARISH ★ 6/10
$44.23 $43.59▲ +1.45%▲ +1.42%—
Jul 16, 2026
14w ago
Insider Cluster
NEUTRAL ★ 5/10
$42.33 $42.04▼ −0.69%▼ −0.52%—
Jul 14, 2026
14w ago
Insider Cluster
NEUTRAL ★ 3/10
$42.43 $42.89▲ +1.08%▲ +1.63%—
Jul 7, 2026
15w ago
Insider Cluster
MIXED ★ 5/10
$41.86 $42.99▲ +2.70%▲ +1.85%—
Jul 7, 2026
15w ago
Insider Cluster
NEUTRAL ★ 4/10
$41.86 $42.99▲ +2.70%▲ +1.85%—
Showing 10 of 41

US Market Status

Market Closed — Opens Tue (17h 28m)

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Report published Jun 11, 2026