CytomX Therapeutics, Inc.
CytomX Therapeutics, Inc. (CTMX) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · CTMX · as of Sep 30, 2025
Ownership Breakdown
112
Institutional Holders
▲ 23 vs Q2
$438.63M
Total Inst. Value
▲ $136.03M vs Q2
160.82M
Shares Outstanding
freeFloat 87.00%
137.51M
13F Shares Held
▲ 4.21M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
CTMX largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VR ADVISER, LLC pharmaceutical preparations | 15.56M | 9.43% | 9.43% | $49.64B | Nov 14, 2025 | ▲ 1.59M |
FMR LLC pharmaceutical preparations | 15.40M | 9.33% | 9.33% | $49.11B | Nov 13, 2025 | ▲ 6.16M |
TANG CAPITAL MANAGEMENT LLC pharmaceutical preparations | 11.07M | 6.71% | 6.71% | $35.30B | Nov 14, 2025 | — held |
PERCEPTIVE ADVISORS LLC pharmaceutical preparations | 9.68M | 5.87% | 5.87% | $30.88B | Nov 14, 2025 | ▲ 2.69M |
VANGUARD GROUP INC pharmaceutical preparations | 8.95M | 5.42% | 5.42% | $28.54B | Nov 7, 2025 | ▼ 432.0K |
ORBIMED ADVISORS LLC pharmaceutical preparations | 8.46M | 5.13% | 5.13% | $26.99B | Nov 14, 2025 | — held |
COMMODORE CAPITAL LP pharmaceutical preparations | 7.69M | 4.66% | 4.66% | $24.54B | Nov 14, 2025 | — held |
BAKER BROS. ADVISORS LP pharmaceutical preparations | 4.25M | 2.58% | 2.58% | $13.56B | Nov 14, 2025 | ▲ 766.6K |
POINT72 ASSET MANAGEMENT, L.P. pharmaceutical preparations | 4.07M | 2.47% | 2.47% | $12.98B | Nov 14, 2025 | ▼ 4.02M |
ADAR1 CAPITAL MANAGEMENT, LLC pharmaceutical preparations | 4.05M | 2.45% | 2.45% | $12.90B | Nov 14, 2025 | ▲ 964.0K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
21
Increased
+21.31M shares11
New Positions
first time holders12
Decreased
−12.82M shares0
Sold Out
fully exitedNet shares change (top 50)
+8.49M
+21.31M / −12.82M
Net new holders
+20
11 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
CTMX insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
11
Buy transactions
4
Sell transactions
2.75
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Chu Yu-Waye Chief Medical Officer | Mar 17, 2026 | Sale | 21,279 | $6.42 | $136.7K | 189.4K | Form 4 ↗ |
McCarthy Sean A. CEO | Mar 17, 2026 | Sale | 118,969 | $6.42 | $764.1K | 1.08M | Form 4 ↗ |
BELVIN MARCIA SVP, Chief Scientific Officer | Mar 17, 2026 | Sale | 31,492 | $6.42 | $202.3K | 300.8K | Form 4 ↗ |
Ogden Christopher Chief Financial Officer | Mar 17, 2026 | Sale | 19,323 | $6.42 | $124.1K | 296.9K | Form 4 ↗ |
Lester Rachael Chief Business Officer | Feb 2, 2026 | Award | 50,000 | $6.09 | $304.5K | 50.0K | Form 4 ↗ |
Lester Rachael Chief Business Officer | Feb 2, 2026 | Award | 50,000 | — | — | 50.0K | Form 4 ↗ |
Lester Rachael Chief Business Officer | Feb 2, 2026 | Award | 20,000 | — | — | 20.0K | Form 4 ↗ |
Chu Yu-Waye Chief Medical Officer | Feb 2, 2026 | Award | 300,000 | $6.09 | $1.83M | 300.0K | Form 4 ↗ |
Chu Yu-Waye Chief Medical Officer | Feb 2, 2026 | Award | 75,000 | — | — | 210.7K | Form 4 ↗ |
BELVIN MARCIA SVP, Chief Scientific Officer | Feb 2, 2026 | Award | 60,000 | — | — | 332.3K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
CytomX Therapeutics, Inc. (CTMX) is primarily owned by institutional investors, who hold approximately 85.5% of total shares outstanding. Company insiders own approximately 13.00%, while retail and public investors account for the remaining 1.49%.
The largest institutional shareholder of CytomX Therapeutics, Inc. is VR ADVISER, LLC, holding approximately 15.56 million shares — equal to 9.43% of outstanding shares — as of September 30, 2025.
A total of 112 institutional investors currently hold CTMX stock, with a combined institutional value of approximately $438,633,856 as of the most recent 13F filing period.
Frequently asked questions
CTMX ownershipCytomX Therapeutics, Inc. (CTMX) is primarily owned by institutional investors, who hold approximately 85.5% of shares. The largest shareholder is VR ADVISER, LLC with a 9.43% stake. Company insiders hold 13.00%. Data sourced from SEC Form 13F as of September 30, 2025.