Monitor upcoming 13F filings for Q4 2026 to see if the selling by Robeco and Assenagon continued or reversed. The 45-day lag means these positions may already be stale — watch for any earnings or clinical catalysts that could have changed the thesis since quarter-end.
Executive Summary
A mixed institutional cluster for Natera (NTRA) in Q3 2026 shows two small asset managers doubling their tiny positions (net +$4.4M bought) while three larger managers trimmed, led by Robeco cutting $18.6M and Assenagon cutting $3.2M, for a net sell-side of $21.8M. The cluster is dominated by active managers but the selling is far larger in dollar terms, suggesting institutional de-risking ahead of the 45-day stale data window.
Key Financial Metrics
Institutional Positions
Net institutional flow: -$17.4M
▲ Buyers (2)
| Institution | Action | Change | Position Value | Value Δ |
|---|---|---|---|---|
| Concurrent Investment Advisors | DOUBLED | +104.3% | $6.5M | $4.4M |
| Mather Group | DOUBLED | +2550% | $22.0K | $21.0K |
▼ Sellers (3)
| Institution | Action | Change | Prev Value | Value Δ |
|---|---|---|---|---|
| Robeco Institutional Asset Management B.v. | TRIM | -45.3% | $110.9M | -$18.6M |
| Assenagon Asset Management | TRIM | -37.4% | $68.1M | -$3.2M |
| Td Waterhouse Canada | TRIM | -38.4% | $20.0K | -$2.0K |
Key Facts
- 2 buyers added $4.4M in new value; 3 sellers reduced by $21.8M, net -$17.4M
- Robeco Institutional Asset Management trimmed 45.3% of its NTRA position, selling $18.6M
- Assenagon Asset Management trimmed 37.4%, selling $3.2M
- Concurrent Investment Advisors doubled its position to $6.5M, the largest buyer
- Mather Group more than doubled a tiny position (from $543 to $22K)
Financial Impact
Net institutional selling of $17.4M in Q3 2026, with $21.8M in total sell-side vs $4.4M in buy-side
Risk Factors
- 13F data is 45+ days stale; the cluster may have already been unwound or reversed
- Small buyers (Mather, Concurrent) have minimal conviction in dollar terms vs large sellers
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-NTRA-2026-Q3 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 20, 2026 6d ago | Insider Cluster | $413.38 $401.37 | ▼ −2.91% | ▼ −1.72% | — |
Oct 20, 2026 6d ago | Institutional Cluster | $413.38 $401.37 | ▲ +2.91% | ▲ +1.72% | — |
Oct 2, 2026 24d ago | Insider Cluster | $425.64 $400.65 | ▲ +5.87% | ▲ +6.42% | — |
Sep 17, 2026 5w ago | Insider Cluster | $369.39 $370.64 | ▼ −0.34% | ▲ +1.21% | — |
Sep 17, 2026 5w ago | Insider Cluster | $369.39 $370.64 | ▼ −0.34% | ▲ +1.21% | — |
Sep 3, 2026 7w ago | Insider Cluster | $328.18 $324.14 | ▼ −1.23% | ▼ −0.68% | — |
Aug 28, 2026 8w ago | Insider Cluster | $321.96 $320.76 | ▲ +0.37% | ▼ −0.31% | — |
Aug 14, 2026 10w ago | Insider Cluster | $314.18 $311.69 | ▼ −0.79% | ▼ −0.12% | — |
Aug 7, 2026 11w ago | Insider Cluster | $318.35 $312.72 | ▼ −1.77% | ▼ −1.45% | — |
Aug 5, 2026 11w ago | Insider Cluster | $265.38 $322.10 | ▼ −21.37% | ▼ −20.76% | — |
US Market Status
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