The dominant signal is Assenagon's near-total exit—a $314M position reduced to $15M. Monitor for any subsequent 13F filings or insider trading patterns that might confirm a fundamental thesis change. The buying side is too small to offset this signal.
Executive Summary
Institutional activity in TMUS during Q3 2026 was mixed: three smaller asset managers added modest positions totaling $17.2M, while three larger sellers—led by Assenagon's near-total exit of a $314M stake—reduced holdings by $307M. The net selling pressure of ~$290M suggests institutional de-risking or rotation out of telecom, though the buying cluster lacks conviction from major active funds.
Key Financial Metrics
Institutional Positions
Net institutional flow: -$289.8M
▲ Buyers (3)
| Institution | Action | Change | Position Value | Value Δ |
|---|---|---|---|---|
| Robeco Institutional Asset Management B.v. | DOUBLED | +159% | $27.2M | $16.4M |
| Farther Finance Advisors | ADD | +27.3% | $4.0M | $756.0K |
| Atwood & Palmer | ADD | +90.9% | $103.0K | $47.0K |
▼ Sellers (3)
| Institution | Action | Change | Prev Value | Value Δ |
|---|---|---|---|---|
| Assenagon Asset Management | NEAR_EXIT | -95.1% | $314.3M | -$299.1M |
| Td Waterhouse Canada | TRIM | -49.4% | $9.6M | -$5.1M |
| Assetmark | TRIM | -40.6% | $6.6M | -$2.8M |
Key Facts
- 3 buyers added $17.2M in net new positions; 3 sellers reduced by $307.0M
- Assenagon Asset Management exited 95.1% of its TMUS position, selling $299.1M worth of shares
- Robeco Institutional Asset Management doubled its stake (+159%), adding $16.4M
- Net institutional outflow of approximately $289.8M in Q3 2026
Financial Impact
Net institutional selling of ~$290M, with one large seller (Assenagon) accounting for $299M of the outflow
Risk Factors
- 13F data is 45+ days stale; positions may have been reversed since quarter-end
- Buyers are small asset managers with limited signal weight; sellers include one large active manager
- No insider buying confluence to corroborate the bullish side of the cluster
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-TMUS-2026-Q3 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 21, 2026 6d ago | Institutional Cluster | $158.79 $146.54 | ▲ +7.71% | ▲ +7.19% | No price |
Jul 23, 2026 13w ago | 8-K | $170.42 $180.09 | ▲ +5.67% | ▲ +5.57% | No price |
Jun 30, 2026 17w ago | Court Ruling | $173.01 $177.37 | ▲ +2.52% | ▲ +2.65% | No price |
Jun 2, 2026 21w ago | Court Ruling | $180.41 $176.00 | ▼ −2.44% | ▼ −2.82% | No price |
May 1, 2026 25w ago | Insider Cluster | $195.97 $193.72 | ▼ −1.15% | ▼ −0.81% | No price |
Mar 26, 2026 30w ago | Court Ruling | $208.48 $211.56 | ▲ +1.48% | ▲ +1.81% | No price |
Mar 25, 2026 31w ago | Court Ruling | $209.24 $208.48 | ▼ −0.36% | ▲ +1.34% | No price |
Feb 28, 2026 34w ago | Institutional Cluster | $216.09 $218.04 | ▲ +0.90% | ▲ +1.82% | No price |
Feb 24, 2026 35w ago | Insider Cluster | $221.87 $218.48 | ▼ −1.53% | ▼ −2.36% | No price |
Feb 24, 2026 35w ago | Insider Cluster | $221.87 $218.48 | ▲ +1.53% | ▲ +2.36% | No price |
US Market Status
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