The near-unanimous active-manager buying at scale suggests a catalyst-driven thesis (likely post-Grail separation or core sequencing margin recovery). With 45-day reporting lag, monitor Q4 2026 13F filings to see if these positions were maintained or reversed. The absence of any passive/index fund activity strengthens the signal — this is conviction-based, not mechanical.
Executive Summary
A strong institutional cluster formed in ILMN during Q3 2026, with 5 active managers accumulating $488.9M net in new positions, overwhelmingly led by Ninety One UK which more than doubled its stake to $372.2M. Two small sellers trimmed a combined $1.3M, making this a near-unanimous bullish signal from active asset managers. The cluster suggests a shared thesis around Illumina's post-Grail turnaround or core sequencing recovery, though the 45-day reporting lag means these positions may have already been adjusted.
Key Financial Metrics
Institutional Positions
Net institutional flow: $487.6M
▲ Buyers (5)
| Institution | Action | Change | Position Value | Value Δ |
|---|---|---|---|---|
| Ninety One Uk | DOUBLED | +37920% | $372.2M | $371.6M |
| Robeco Institutional Asset Management B.v. | ADD | +52.5% | $128.4M | $74.3M |
| Td Waterhouse Canada | DOUBLED | +599.2% | $33.9M | $30.5M |
| Czech National Bank | NEW | +0% | $11.9M | $11.9M |
| Concurrent Investment Advisors | ADD | +30.2% | $1.2M | $609.0K |
▼ Sellers (2)
| Institution | Action | Change | Prev Value | Value Δ |
|---|---|---|---|---|
| Assenagon Asset Management | TRIM | -41.5% | $24.6M | -$2.2M |
| Fjarde Ap-Fonden /Fourth Swedish National | TRIM | -28.6% | $8.5M | $946.0K |
Key Facts
- 5 institutional buyers added $488.9M in net new exposure, while 2 sellers trimmed only $1.3M
- Ninety One UK was the dominant buyer, increasing its stake from $629K to $372.2M (a 37,920% increase)
- Robeco Institutional Asset Management added $74.3M (52.5% increase to $128.4M)
- TD Waterhouse Canada nearly 7x'd its position to $33.9M
- Czech National Bank initiated a new $11.9M position
- Both sellers (Assenagon and Fjarde AP-Fonden) trimmed modest positions, with combined net sales of only $1.3M
- All 7 institutions are active asset managers — no passive/index funds dominate this cluster
Financial Impact
5 institutions accumulated $488.9M in net new positions while 2 reduced holdings by $1.3M, for a net inflow of approximately $487.6M into ILMN during Q3 2026
Risk Factors
- 13F data is 45+ days stale — these positions may have been partially or fully unwound since quarter-end
- Ninety One UK's extreme position sizing (from near-zero to $372M) could reflect a concentrated bet that may be volatile if the thesis fails
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-ILMN-2026-Q3 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 20, 2026 5d ago | Institutional Cluster | $282.86 | awaiting T+5 | — | — |
Oct 13, 2026 12d ago | 8-K | $271.76 $282.86 | ▲ +4.08% | ▲ +3.63% | — |
Oct 12, 2026 14d ago | Institutional Cluster | $276.67 $262.66 | ▼ −5.06% | ▼ −3.57% | — |
Oct 7, 2026 19d ago | SC 13G | $267.76 $271.76 | ▲ +1.49% | ▲ +2.47% | — |
Sep 30, 2026 26d ago | Court Ruling | $265.72 $264.57 | ▼ −0.43% | ▼ −1.73% | — |
Aug 27, 2026 8w ago | Insider Cluster | $215.59 $218.22 | ▲ +1.22% | ▲ +1.11% | — |
Aug 21, 2026 9w ago | Insider Cluster | $223.22 $213.63 | ▲ +4.30% | ▲ +4.77% | — |
Aug 17, 2026 9w ago | 8-K | $188.29 $224.99 | ▲ +19.49% | ▲ +19.69% | — |
Aug 12, 2026 10w ago | 8-K | $192.91 $205.00 | ▲ +6.27% | ▲ +6.71% | — |
Aug 6, 2026 11w ago | Insider Cluster | $187.96 $190.89 | ▼ −1.56% | ▼ −1.16% | — |
US Market Status
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