STRO

Sutro Biopharma Inc Cross-source read$15.34 0.90%
Health CareCUSIP 869367201· EOD Sep 18, 2026

Among active 13F managers last quarter, 10 opened and 9 added, while 11 reduced; the largest holder to move was Perceptive Advisors LLC (+82%). No open-market insider trades in the last 180 days.

Tracked 13F holders
71
21 in Q2 2026 filings
13F value (tracked)
$451.4M
Smart-money readBullish
Net sellingNet buying
Funds · active managers, latest 13F
19 adding · 11 trimming
Insiders · Form 4 open-market, 180d
0 buying · 0 selling
US House · STOCK Act, 180d
0 buying · 0 selling

Funds lean in and no leg opposes.

Price & smart-money activity

$15.34 0.90%5Y -92.0%
$5.33$67.36$129.39$191.42$253.44202120222023202420252026252325993
Hover for who · click for detailEnd-of-day closing prices52w $7.30 – $40.91

Who owns STRO?

71 tracked 13F filers · ranked by shares held

71 tracked 13F filers disclose a position in STRO as of the latest SEC 13F filings, a combined $451.4M in reported value. Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

#FundSharesPosition valueLast moveAs ofHistory
1Perceptive Advisors LLC1.3M
$43.3M
+82%
Added · +590K sh
Q2 2026
2BVF Inc1.3M
$41.6M
Held
Q2 2026
3BlackRock, Inc.1.1M
$37.3M
+382%
Added · +890K sh
Q2 2026
4Affinity Asset Advisors, LLC1.1M
$26.6M
+43%
Added · +321K sh
Q1 2026
5Samsara BioCapital, LLC1.1M
$35.3M
Held
Q2 2026
6Kynam Capital Management, LP873K
$29.0M
Held
Q2 2026
7Orbimed Advisors LLC744K
$24.7M
−7.1%
Reduced · −57K sh
Q2 2026
8Vanguard Capital Management LLC694K
$23.0M
−3.6%
Reduced · −26K sh
Q2 2026
9Eventide Asset Management, LLC585K
$19.4M
−18%
Reduced · −130K sh
Q2 2026
10ADAR1 Capital Management, LLC524K
$13.1M
+682%
Added · +457K sh
Q1 2026
11Velan Capital Investment Management LP512K
$17.0M
Held
Q2 2026
12Balyasny Asset Management L.P.466K
$11.6M
+102%
Added · +236K sh
Q1 2026
13Woodline Partners LP458K
$15.2M
+0.1%
Added · +588 sh
Q2 2026
14UBS Group AG393K
$9.8M
50×
Added · +385K sh
Q1 2026
15Geode Capital Management, LLC390K
$12.9M
+127%
Added · +218K sh
Q2 2026
16State Street Corp306K
$10.2M
+487%
Added · +254K sh
Q2 2026
17Merck & Co., Inc.272K
$9.0M
New
+272K sh
Q2 2026
18Acuta Capital Partners, LLC270K
$9.0M
+0.3%
Added · +826 sh
Q2 2026
19Point72 Asset Management, L.P.238K
$7.9M
−66%
Reduced · −454K sh
Q2 2026
20KVP Capital Advisors, LP227K
$7.5M
Held
Q2 2026
21Marshall Wace, LLP223K
$5.5M
+160%
Added · +137K sh
Q1 2026
22Millennium Management LLC210K
$5.2M
−50%
Reduced · −208K sh
Q1 2026
23Adage Capital Partners GP, L.L.C.200K
$5.0M
Held
Q1 2026
24Vanguard Portfolio Management LLC198K
$6.6M
New
+198K sh
Q2 2026
25Vanguard Fiduciary Trust Co104K
$3.5M
+9.9%
Added · +9K sh
Q2 2026

Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

Is STRO being bought or sold by institutions?

Last quarter, 10 funds opened a new position in STRO and 9 added to an existing one, while 11 reduced. Based on 13F filings from active, signal-eligible managers (passive index funds and other mechanical holders are excluded from this count).

Opened
10
funds took a first position
Added
9
added to an existing position
Reduced
11
reduced, still holding
Biggest moves · ranked by size of the change, positions above a floor

Funds that own STRO also own

CompanyCo-held byTheir position there
Intuitive Surgical IncISRG29 funds$8.5B
Eli Lilly & CoLLY28 funds$26.1B
Boston Scientific CorpBSX28 funds$2.8B
Viridian Therapeutics IncVRDN28 funds$427.7M
Revolution Medicines IncRVMD27 funds$2.5B
Nvidia CorpNVDA26 funds$112.3B
Broadcom IncAVGO26 funds$44.3B
Unitedhealth Group IncUNH26 funds$14.4B
Microsoft CorpMSFT25 funds$55.0B
Micron Technology IncMU25 funds$22.9B
Lam Research CorpLRCX25 funds$14.0B
Arista Networks IncANET25 funds$7.1B

Ranked by how many of STRO's tracked holders also hold each name. The last column is those co-holders' combined reported position in that name, not in STRO.

Insider activity (Form 4)

Full insider page →
Net · 180d
$0
0 open-market transactions
DateInsiderRoleActionSharesValue
Oct 15, 2025Matsui ConnieDirectorBuy (P)50K$40K
Oct 15, 2025Chow Gregory K.CFOBuy (P)20K$16K
Oct 15, 2025Chung JaneChief Executive Officer, DirectorBuy (P)13K$10K
Oct 15, 2025Gerber Hans-PeterCHIEF SCIENTIFIC OFFICERBuy (P)17K$14K
Oct 15, 2025Pauling DavidChief Admin. Ofcr. & GCBuy (P)13K$10K
Jan 29, 2024Vasquez NickiCHIEF PORT. STRAT & ALNCE OFCRSell (S)12K$61K
Aug 28, 2023Shtylla BrunildaChief Business OfficerSell (S)15K$73K
Aug 25, 2023Shtylla BrunildaChief Business OfficerSell (S)12K$53K
Mar 14, 2022Newell William JCEO, DirectorBuy (P)10K$78K
Sep 28, 2021Vasquez NickiChief Port. Strat & Alnce OfcrSell (S)4K$73K
Jan 26, 2021Hallam TrevorChief Scientific OfficerSell (S)
2 lots, same day
2K$62K
Dec 28, 2020Hallam TrevorChief Scientific OfficerSell (S)2K$54K

One row per insider, day and transaction code; shares and value are summed across the lots. Every lot is on the full insider page and in the filing.

Do institutions, insiders and Congress agree?

Mixed signals

Where institutional funds (13F), corporate insiders (Form 4) and US House members (STOCK Act) are buying or selling the same name in the same window. Green is buying, red is selling.

SEC EDGAR 13F + Form 4 + US House STOCK Act{ }get_ticker_confluence · API & MCP

Signals by source

Insiders and Congress: last 180 days. Funds: latest 13F, top 100 holders incl. passive

SourceBuyingSellingNet
13F funds
Top 100 holders by value, passive included; the hero counts active managers only
2116
Insiders
Form 4 open-market
00$0
US House
STOCK Act trades
00$0
Sector rotation
STRO is in Health Care, which smart money is rotating OUT OF
$7.6B

Capital Rotation reports where institutional capital disclosed rotating, as of the latest public SEC 13F filings. It is data, not investment advice, a recommendation, or a prediction. Filings lag about 45 days and cover long US equity positions only. Past disclosed flows do not indicate future prices. Do your own research; consult a licensed advisor.

Institutional ownership over time

21 tracked filers in Q2 2026 filingsstill filing
03161Q4 2025Q1 2026Q2 2026
tracked filers holding their reported valueQ2 2026 filings so far: $70.5M
Each bar counts tracked filers with a position in that quarter's filings, so the newest bar excludes filers still on an earlier quarter. Arkolith's tracked universe has grown over this window; part of any long-run rise is coverage, not new buyers.

Share classes

Class13F holdersValue held
STROthis pageEquity71 funds$451.4M
869367102Stock5 funds$5K

Same issuer, multiple share classes. The consensus leaderboards count this company once across all classes; this is the per-class detail.

Recent filings

15 most recent

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Connected entities for STRO

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Ask your agent what changed in STRO

This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.

Copy-paste
curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://arkolith.com/api/v1/stocks/STRO/capital-change-brief"
Ask your agent
Use Arkolith's capital_change_brief for STRO.
Tell me what changed, whether insider activity
corroborates it, and cite the SEC evidence.

13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for STRO. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes.