Summit Therapeutics

SMMT · NASDAQ

$16.09+$0.52 (+3.34%)TodayMarket closed · Oct 20, 7:59 PM ET

Prev close $15.57

Who owns SMMT

Largest institutional holders, from their latest 13F filings

The 10 largest institutions hold 90.0% of SMMT’s shares.

Duggan (Robert William)71.9%
Zanganeh (Mahkam)4.5%
Baker Bros. Advisors LP4.1%
Xia (Yu)4.0%
Next 6 largest institutions5.4%
All other shareholders10.0%

Top institutional holders of SMMT
Holder	Shares	% of shares	Change, last filing	Filed
Duggan (Robert William)	573.88M	71.94%	+3.81M	Jun 12, 2026
Zanganeh (Mahkam)	36.03M	4.52%	+293.49K	Apr 15, 2026
Baker Bros. Advisors LP	32.79M	4.11%	−3.60M	Jun 30, 2026
Xia (Yu)	32.06M	4.02%	+533.62K	Apr 15, 2026
Fidelity Management & Research Company LLC	10.04M	1.26%	−809.25K	Jun 30, 2026
State Street Investment Management (US)	9.54M	1.20%	+2.51M	Jun 30, 2026
BlackRock Institutional Trust Company, N.A.	7.57M	0.95%	+903.68K	Jun 30, 2026
Vanguard Capital Management, LLC	5.73M	0.72%	+22.68K	Jun 30, 2026
UBS Financial Services, Inc.	5.23M	0.66%	+1.55M	Jun 30, 2026
Vanguard Portfolio Management, LLC	5.04M	0.63%	−191.06K	Jun 30, 2026

Largest mutual fund holders

Top mutual fund holders of SMMT
Holder	Shares	% of shares	Change, last filing	Filed
State Street SPDR S&P Biotech ETF	7.85M	0.98%	+533.81K	Aug 31, 2026
Vanguard Total Stock Market Index Fund	3.73M	0.47%	+17.69K	Jul 31, 2026
Vanguard Small-Cap Index Fund	2.68M	0.34%	+5.05K	Jul 31, 2026
Fidelity Growth Company Fund	2.65M	0.33%	+0	Jul 31, 2026
T. Rowe Price Health Sciences Fund	2.53M	0.32%	−3.65M	Jun 30, 2026

Insider trades

Form 4 filings by officers, directors and large holders

Over the last 6 months, insiders bought $103.62M (6 trades) of SMMT on the open market, with no sales.

Latest SMMT insider transactions
Insider	Date	Type	Shares	Price	Value
Anand Bhaskar	Oct 8, 2026	Award	100.00K	—	—
Zanganeh Mahkam	Jun 12, 2026	Buy	3.81M	$13.12	$49.99M
DUGGAN ROBERT W	Jun 12, 2026	Buy	3.81M	$13.12	$49.99M
Soni Manmeet Singh	Jun 4, 2026	Buy	25.00K	$14.43	$360.75K
Soni Manmeet Singh	Jun 4, 2026	Buy	25.00K	$14.46	$361.50K
Zanganeh Mahkam	Jun 4, 2026	Buy	100.00K	$14.60	$1.46M
DUGGAN ROBERT W	Jun 4, 2026	Buy	100.00K	$14.60	$1.46M

Short interest

Settled Sep 30, 2026

Shares short: 41.16M
Days to cover: 4.84
% of shares outstanding: 5.16%
Average daily volume: 8.50M
Change since last report: +0.2%

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