The simultaneous open-market buying by both co-CEOs and the CFO is a rare and credible bullish signal at a large-cap biotech. While the dollar amount is small relative to market cap, the unanimity and C-suite participation carry disproportionate weight. Monitor for upcoming catalysts (pipeline updates, partnership news, or earnings) that may have motivated this cluster. The cross-filing amplifiers (cluster + earnings/agreement/press context) suggest elevated odds of near-term positive news flow.
Price Chart
Executive Summary
Both co-CEOs and the COO/CFO of Summit Therapeutics made open-market purchases totaling $3.28M on June 4, 2026, at ~$14.50-$14.60 per share. This is a rare cluster of C-suite insider buying at a $11.7B market cap company, representing ~0.03% of market cap — a small but symbolically strong signal from the top executives.
Key Financial Metrics
Key Facts
- Both co-CEOs (Robert Duggan and Mahkam Zanganeh) each purchased 100,000 shares ($1.46M each) on June 4, 2026
- COO/CFO Manmeet Singh purchased 25,000 shares ($362K) on the same day
- Total cluster value: $3.28M in open-market purchases
- All purchases were open-market (code P), not option exercises or grants
- Cluster represents ~0.03% of SMMT's $11.7B market cap
- No insider sales in the cluster window
Financial Impact
$3.28M in insider purchases, ~0.03% of market cap
Risk Factors
- Insider buying at this scale (~0.03% of market cap) is not economically material — could be signaling confidence without moving the stock
- Historical calibration shows past SMMT reports had negative T+20 outcomes (avg -19%), suggesting the stock may not follow this signal
- No specific catalyst identified — buying could be pre-arranged or opportunistic rather than event-driven
Market Snapshot
Investment Themes
Documents Analyzed
This report is based on 1 SEC document filed with EDGAR.
| Document | Accession Number |
|---|---|
| CLUSTER Data (Synthetic) | cluster-SMMT-1780611038028 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Sep 15, 2026 17d ago | 8-K | $17.40 $17.85 | ▲ +2.59% | ▲ +1.77% | $16.75 (−3.71%) |
Sep 14, 2026 18d ago | 8-K | $18.42 $16.90 | ▼ −8.25% | ▼ −8.36% | $16.75 (−9.04%) |
Sep 3, 2026 29d ago | 8-K | $17.13 $17.55 | ▲ +2.45% | ▲ +3.60% | $16.75 (−2.19%) |
Aug 26, 2026 5w ago | 8-K | $14.23 $14.60 | ▲ +2.60% | ▲ +2.72% | $16.75 (+17.74%) |
Aug 5, 2026 8w ago | 8-K | $13.53 $15.10 | ▲ +11.60% | ▲ +11.25% | $16.75 (+23.84%) |
Jul 22, 2026 10w ago | 8-K | $14.74 $12.80 | ▼ −13.16% | ▼ −10.76% | $16.75 (+13.67%) |
Jun 12, 2026 16w ago | Insider Cluster | $14.01 $13.75 | ▼ −1.86% | ▼ −2.53% | $16.75 (+19.59%) |
Jun 12, 2026 16w ago | Institutional Cluster | $14.01 $13.75 | ▼ −1.86% | ▼ −2.53% | $16.75 (+19.59%) |
Jun 11, 2026 16w ago | Institutional Cluster | $13.08 $14.07 | ▲ +7.57% | ▲ +7.14% | $16.75 (+28.10%) |
Jun 9, 2026 16w ago | S-3ASR | $13.05 $13.88 | ▼ −6.36% | ▼ −2.93% | $16.75 (−28.39%) |
US Market Status
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