The Q2 2026 institutional cluster is dominated by passive/index funds, which reduces its signal value as a fundamental catalyst. The 45-day reporting lag means these positions may already be stale. Monitor for any insider buying or active manager filings (e.g., 13D) to confirm a genuine thesis shift.
Executive Summary
Assembly Biosciences (ASMB) saw a strong institutional accumulation cluster in Q2 2026, with 6 buyers adding $25.8M in net new holdings versus just 1 seller trimming a negligible $55K. The buying was dominated by mega-passive funds (BlackRock, State Street, Goldman Sachs, Geode) all doubling or more than doubling their positions, suggesting broad index-driven or factor-based accumulation rather than a concentrated activist or fundamental thesis. The lone seller (Citigroup) trimmed a small position, further confirming the net bullish institutional flow.
Key Financial Metrics
Institutional Positions
Net institutional flow: $25.8M
▲ Buyers (6)
| Institution | Action | Change | Position Value | Value Δ |
|---|---|---|---|---|
| BlackRock | DOUBLED | +278.2% | $21.1M | $15.4M |
| State Street | DOUBLED | +203.3% | $4.7M | $3.2M |
| Goldman Sachs | DOUBLED | +280.7% | $3.8M | $2.8M |
| Geode | DOUBLED | +110.9% | $7.7M | $4.0M |
| Morgan Stanley | ADD | +36.8% | $1.2M | $325.0K |
| American Century Companies | ADD | +44.6% | $364.0K | $110.0K |
▼ Sellers (1)
| Institution | Action | Change | Prev Value | Value Δ |
|---|---|---|---|---|
| Citigroup | TRIM | -29.8% | $180.0K | -$54.8K |
Key Facts
- 6 institutional buyers added $25.8M in net new holdings during Q2 2026
- BlackRock more than doubled its position to $21.1M (278% increase)
- State Street, Goldman Sachs, and Geode each doubled or more than doubled their stakes
- Only 1 seller (Citigroup) trimmed a small position by $55K
- All major buyers are mega-passive/index-tracker funds, not active fundamental managers
- No insider open-market buying was detected during the same period (confluence score 20/100, divergent)
Financial Impact
Net institutional accumulation of $25.8M across 6 buyers, with total buyer holdings reaching $38.9M. The largest single addition was BlackRock's $15.4M increase.
Risk Factors
- 45-day 13F reporting lag means positions may already be unwound
- Passive/index fund buying may reflect rebalancing rather than conviction
- No insider buying to corroborate the institutional thesis
Market Snapshot
Investment Themes
Documents Analyzed
This report is based on 1 institutional 13F filing from SEC EDGAR.
| Document | Accession Number |
|---|---|
| INST-CLUSTER Data (Synthetic) | inst-cluster-ASMB-2026-Q2 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Aug 15, 2026 10w ago | Institutional Cluster | $30.01 $35.28 | ▲ +17.56% | ▲ +18.75% | — |
Aug 13, 2026 10w ago | Press Release | $32.95 $34.38 | ▲ +4.34% | ▲ +5.71% | — |
Jun 11, 2026 19w ago | Institutional Cluster | $22.53 $24.15 | ▲ +7.19% | ▲ +6.76% | — |
Jun 5, 2026 20w ago | 8-K | $22.56 $23.34 | ▲ +3.48% | ▲ +1.37% | — |
May 22, 2026 22w ago | 424B5 | $28.75 $26.92 | ▲ +6.37% | ▲ +7.45% | — |
May 22, 2026 22w ago | 8-K | $28.34 $26.92 | ▼ −5.01% | ▼ −6.67% | — |
May 22, 2026 22w ago | Press Release | $28.34 $26.92 | ▼ −5.01% | ▼ −6.67% | — |
May 7, 2026 24w ago | Press Release | $29.74 $30.30 | ▲ +1.88% | ▲ +0.42% | — |
Mar 30, 2026 30w ago | EFFECT | $26.64 $28.53 | ▲ +7.09% | ▲ +2.79% | — |
Mar 19, 2026 31w ago | Press Release | $28.46 $27.70 | ▼ −2.67% | ▼ −0.52% | — |
US Market Status
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