IMRX Immuneering Corp
Executive Summary
Five mega-passive institutional investors (Vanguard, BlackRock, State Street, Fidelity, Morgan Stanley) significantly increased their IMRX positions in Q3 2025, with aggregate holdings rising from $6.8M to $86.5M — a net addition of $79.7M. Fidelity alone added $60.8M, including a massive 3,876% share increase. The cluster is entirely passive/index-driven, reflecting likely index reconstitution or inclusion in a new benchmark, not active fundamental conviction.
Key Financial Metrics
Institutional Positions
Net institutional flow: $79.7M
▲ Buyers (5)
| Institution | Action | Change | Position Value | Value Δ |
|---|---|---|---|---|
| Fidelity | DOUBLED | +3876% | $61.5M | $60.8M |
| Vanguard | DOUBLED | +128.5% | $16.9M | $13.3M |
| BlackRock | ADD | +61.1% | $4.8M | $3.3M |
| Morgan Stanley | ADD | +46.6% | $2.1M | $1.4M |
| State Street | ADD | +77.6% | $1.2M | $882.0K |
Actionable Insight
The cluster is entirely passive/index-driven, likely reflecting IMRX's inclusion in a new index or benchmark rebalancing, not active fundamental conviction. With historical IMRX reports showing a -7.58% average T+20 return and only 25% win rate, traders should not interpret this as a bullish signal. Monitor for any active manager 13F filings in subsequent quarters for genuine conviction signals.
Key Facts
- 5 institutions added $79.7M net to IMRX positions in Q3 2025, with zero sellers
- Fidelity led with a $60.8M increase (3,876% share growth to 8.79M shares)
- All buyers are mega-passive/index funds (Vanguard, BlackRock, State Street, Fidelity, Morgan Stanley)
- No active managers or hedge funds participated in the cluster
- Historical reports on IMRX show a -7.58% average T+20 return and only 25% win rate
Financial Impact
5 institutions accumulated $79.7M in new positions, bringing total disclosed holdings to $86.5M
Risk Factors
- Passive buying provides no fundamental thesis — positions may be unwound at next rebalance
- Historical IMRX reports show poor post-filing performance (-7.58% avg T+20)
- 13F data is 45+ days stale; positions may have already been reduced
Market Snapshot
Documents Analyzed
This report is based on 1 institutional 13F filing from SEC EDGAR.
| Document | Accession Number |
|---|---|
| INST-CLUSTER Data (Synthetic) | inst-cluster-IMRX-2025-Q3 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
|
Jun 11, 2026
3d ago
|
Institutional Cluster
| $3.90 awaiting T+1 | awaiting T+1 | — | — |
|
Jun 1, 2026
13d ago
|
8-K
| $4.28 $4.55 | ▲ +6.31% | ▲ +7.00% | — |
|
May 15, 2026
4w ago
|
Press Release
| $5.16 $4.87 | ▼ −5.62% | ▼ −5.56% | — |
|
Apr 21, 2026
7w ago
|
Press Release
| $5.89 $6.13 | ▲ +4.07% | ▲ +4.47% | — |
|
Apr 20, 2026
7w ago
|
DEFA14A
| $5.55 $5.89 | ▲ +6.13% | ▲ +5.11% | — |
|
Mar 6, 2026
14w ago
|
Press Release
| $5.33 $5.62 | ▲ +5.44% | ▲ +4.59% | — |
US Market Status
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