The unanimous institutional accumulation, particularly Assenagon's large $594M addition, suggests a shared positive view on Berkshire's insurance float growth or capital allocation. Monitor upcoming 13F filings for confirmation of continued accumulation or potential unwinding.
Executive Summary
Four institutional asset managers increased their BRK-B positions in Q3 2026, led by Assenagon Asset Management's $594M addition. The cluster shows a clear bullish conviction with $605.8M in net buying and no institutional sellers, though the 45-day reporting lag means positions may have shifted since quarter-end.
Key Financial Metrics
Institutional Positions
Net institutional flow: $605.8M
▲ Buyers (4)
| Institution | Action | Change | Position Value | Value Δ |
|---|---|---|---|---|
| Assenagon Asset Management | ADD | +36.1% | $2.3B | $594.3M |
| Mather Group | ADD | +25.2% | $28.8M | $5.7M |
| Vontobel Holding | ADD | +28.4% | $21.1M | $4.6M |
| Atwood & Palmer | ADD | +62.1% | $3.1M | $1.2M |
Key Facts
- 4 institutions added to BRK-B positions in Q3 2026, with zero sellers
- Aggregate net buying of $605.8M across all tracked funds
- Assenagon Asset Management added $594.3M, representing 98% of total net buying
- All four buyers are active asset managers, not passive/index funds
- 13F data is 45+ days stale; current positions may differ
Financial Impact
4 institutions accumulated $605.8M in new BRK-B positions during Q3 2026, with total holdings rising to $2.32B. No institutional selling was detected.
Risk Factors
- 13F data is stale by 45+ days; the cluster may have already been reversed
- No insider buying corroboration is available to strengthen the signal
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-BRK-B-2026-Q3 |
Track record builds as more directional reports settle.
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 16, 2026 10d ago | Institutional Cluster | $532.02 $548.56 | ▲ +3.11% | ▲ +3.25% | — |
Oct 12, 2026 14d ago | Institutional Cluster | $517.60 $532.23 | ▲ +2.83% | ▲ +4.32% | — |
Oct 7, 2026 20d ago | SC 13G/A | $511.05 $525.68 | ▲ +2.86% | ▲ +3.14% | — |
Sep 21, 2026 4w ago | 3 | $502.88 $502.31 | ▼ −0.11% | ▲ +1.07% | — |
Aug 11, 2026 10w ago | 8-K | $516.15 $503.09 | ▼ −2.53% | ▼ −2.13% | — |
Mar 13, 2026 32w ago | DEFA14A | $492.26 $480.00 | ▼ −2.49% | ▼ −0.45% | — |
Mar 13, 2026 32w ago | DEFA14A | $492.26 $480.00 | ▼ −2.49% | ▼ −0.45% | — |
Mar 5, 2026 33w ago | 8-K | $499.78 $491.74 | ▼ −1.61% | ▲ +0.63% | — |
US Market Status
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