AMLX Amylyx Pharmaceuticals, Inc.
Executive Summary
Four mega-passive institutional investors (BlackRock, State Street, Fidelity, Morgan Stanley) significantly increased their positions in Amylyx Pharmaceuticals during Q3 2025, with Fidelity and Morgan Stanley more than tripling their holdings. The aggregate buying totaled $300.2M in current value, a net increase of $235.8M, indicating strong passive rebalancing or index-driven accumulation rather than active fundamental conviction. The cluster is dominated entirely by passive/index funds, which weakens the signal as a directional thesis.
Key Financial Metrics
Institutional Positions
Net institutional flow: $235.8M
▲ Buyers (4)
| Institution | Action | Change | Position Value | Value Δ |
|---|---|---|---|---|
| BlackRock | ADD | +29.6% | $97.0M | $61.7M |
| State Street | ADD | +60.7% | $22.0M | $15.6M |
| Fidelity | DOUBLED | +273.3% | $154.6M | $135.1M |
| Morgan Stanley | DOUBLED | +300.6% | $26.5M | $23.4M |
Actionable Insight
The cluster is dominated by passive index rebalancing, not active fundamental conviction. Monitor for any active manager 13F filings or insider buying to confirm a genuine thesis. Given the poor historical calibration on AMLX (avg -13% T+20), treat this as noise unless a catalyst emerges.
Key Facts
- 4 mega-passive institutions added $235.8M in net new holdings during Q3 2025
- Fidelity doubled its position (+273.3%) to $154.6M, the largest dollar increase
- Morgan Stanley tripled its position (+300.6%) to $26.5M
- Zero institutional sellers in the cluster
- All buyers are mega-passive/index funds — no active managers, hedge funds, or activists involved
- Historical AMLX reports show -12.99% average T+20 return with 25% win rate, suggesting prior calls were over-optimistic
Financial Impact
4 institutions accumulated $300.2M in current holdings, net increase of $235.8M from prior quarter. No selling activity.
Risk Factors
- Passive buying provides no fundamental signal — may reverse on next rebalance
- Historical AMLX reports show poor T+20 performance (-13% avg), suggesting over-scoring bias
- 13F data is 45+ days stale; positions may have already been unwound
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-AMLX-2025-Q3 |
Track record builds as more directional reports settle.
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
|
Jun 11, 2026
2d ago
|
Institutional Cluster
| $13.46 awaiting T+20 | awaiting T+20 | — | — |
|
Apr 23, 2026
7w ago
|
DEFA14A
| $17.32 $13.61 | ▼ −21.42% | ▼ −26.05% | — |
|
Mar 2, 2026
14w ago
|
Insider Cluster
| $15.30 $12.76 | ▼ −16.60% | ▼ −8.66% | — |
|
Feb 23, 2026
15w ago
|
Insider Cluster
| $13.90 $13.53 | ▲ +2.66% | ▼ −1.28% | — |
US Market Status
Subscribe to SecBot
Get Real-Time SEC Filing Intelligence
Comprehensive SEC filing analysis delivered the moment filings hit EDGAR. Sentiment scoring, impact analysis, and actionable insights for every material event.
Try SecBot Free Coming soon: SecBot Pro with alerts, watchlists, and API access