$STRO

$8.87 -$0.02 (0.17%) Close

$STRO Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 16.6M shares outstanding

Who owns STRO?

By type of holder

Institutions 99.3% Insiders 0.3% Everyone else 0.4%

Concentration Top 10 holders own 57.4%

Perceptive Advisors LLC 7.9% · BVF Inc/il 7.6%

Institutional ownership

99.3%

+12.6 pts vs last qtr

Institutional holders

+21 vs last qtr

Net shares bought

+2.1M

by institutions in Q2 2026

New / sold out

40 / 19

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

BlackRock, Inc. +890.0K
Perceptive Advisors LLC +589.5K

Biggest sellers in Q2 2026

Ra Capital Management, L.P. SOLD OUT −715.3K
Point72 Asset Management, L.P. −454.3K

Who is planning to sell?

Notices of proposed sale, last 12 months

$131K

1 notice from 1 person

Shares covered

8.9K

0.05% of the company

Arranged in advance

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

Barbara Leyman Former officer $131K

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2024–FY2025

+9.8%

+9.84% a year

Each share's claim on the business

−9.0%

shrank without buying or selling a share

Spent on buybacks vs paid in stock

— vs $38.7M

over 2 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years31% 3–5 years7% 1–3 years14% Under 1 year48%

Quarterly turnover

25.0%

of institutional shares changed hands

Top 10 managers, median time held

1.3 years

Super Investors

Investment managers reporting STRO on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
PA Perceptive Advisors LLC	1.3M	7.87%	+589.5K (+82.4%)	Q1 '26	0.7%
Shares held by quarter Peak holding1.3M (Q2'26) Change over 8 quarters+1.3M Share of the company7.870% Perceptive Advisors LLC's full portfolio →
BI BVF Inc/il	1.3M	7.55%	Unchanged	Q1 '26	1.1%
Shares held by quarter Peak holding1.3M (Q1'26) Change over 8 quarters+1.3M Share of the company7.550% BVF Inc/il's full portfolio →

Perceptive Advisors LLC

1.3M

% of company

7.87%

Change vs last qtr

+589.5K (+82.4%)

Held since

Q1 '26

BVF Inc/il

1.3M

% of company

7.55%

Change vs last qtr

Unchanged

Held since

Q1 '26

28 more super investors behind a free account

See every manager holding Sutro Biopharma Inc, how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting STRO on Form N-PORT; together they hold 16.7% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
EH Eventide Healthcare & Life Sciences Fund Mutual Fund Series Trust	$19.4M	585.3K	3.53%	1.09%	June 30, 2026
VT Vanguard Total Stock Market Index Fund Vanguard Index Funds	$16.7M	501.5K	3.02%	0.00%	June 30, 2026

Eventide Healthcare & Life Sciences Fund

Mutual Fund Series Trust

Position value

$19.4M

% of company

3.53%

% of the fund

1.09%

As of

June 30, 2026

Vanguard Total Stock Market Index Fund

Vanguard Index Funds

Position value

$16.7M

% of company

3.02%

% of the fund

0.00%

As of

June 30, 2026

23 more funds behind a free account

See every fund holding Sutro Biopharma Inc and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
GH Gerber Hans-Peter Insider	12.4K	0.07%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company0.070% Gerber Hans-Peter's insider activity →
NW Newell William J Insider	9.3K	0.06%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company0.060% Newell William J's insider activity →

Gerber Hans-Peter

Insider

12.4K

% of company

0.07%

Change vs last qtr

—

Held since

—

Newell William J

Insider

9.3K

% of company

0.06%

Change vs last qtr

—

Held since

—

9 more holders behind a free account

See every insider and 5%+ holder of Sutro Biopharma Inc.

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