SMMT Summit Therapeutics Inc.

NASDAQ
$15.61

Summit Therapeutics Inc. (SMMT) Insider Activity

What the officers, directors and large holders did with their own shares. Only open-market purchases and sales count toward the totals — grants, option exercises and shares withheld for tax are compensation mechanics, not decisions, and they're listed separately below.

Insider signal Bullish Insiders bought more than they sold over this window — uncommon at any size.
Cluster activity 0 buyers in the last 30 days 0 buyers in the last 90 days 0 sellers in the last 90 days
Insiders buying
4
9 transactions
Insiders selling
0
0 transactions
Purchases
$114.6M
8,456,977 shares
Sales
$0
0 shares
Net activity
$114.6M
purchases less sales

Where they traded

Buy Sell Dot area is proportional to transaction value.

Last open-market purchase: June 12, 2026 , by DUGGAN ROBERT W .

Recent open-market activity

Date Insider Role Action Shares Price Value Held after
DUGGAN ROBERT W Co-Chief Executive Officer Buy 3,810,000 $13.12 $50.0M 573,883,879
Zanganeh Mahkam Co-Chief Executive Officer Buy 3,810,000 $13.12 $50.0M 573,883,879
DUGGAN ROBERT W Co-Chief Executive Officer Buy 100,000 $14.60 $1.5M 25,824,474
Zanganeh Mahkam Co-Chief Executive Officer Buy 100,000 $14.60 $1.5M 25,824,474
Soni Manmeet Singh 2 fills COO and CFO Buy 50,000 $14.45 $722.3K 3,123,603
Xia Yu Director Buy 533,617 $18.74 $10.0M 32,057,147
DUGGAN ROBERT W Co-Chief Executive Officer Buy 26,680 $18.74 $500.0K 76,680
Zanganeh Mahkam Co-Chief Executive Officer Buy 26,680 $18.74 $500.0K 76,680

Form 4s are due within two business days of a transaction, so this is close to real time — unlike the quarterly 13F data on the Institutional tab. A single large sale often reflects a prearranged 10b5-1 plan rather than a fresh view, so read a pattern of sales rather than any one of them.