Who owns CytomX Therapeutics (CTMX)
Which tracked institutional funds hold CTMX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See CTMX company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
29 tracked funds added or opened CTMX while 58 trimmed or exited it between 2026-Q1 and 2026-Q2 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
CTMX’s largest tracked holder by dollar value, FMR LLC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in CTMX divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 176 tracked filers holding CTMX, 114 increased or opened the position and 80 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in CTMX between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 6
- TUDOR INVESTMENT CORP ET AL$5M
- DV EQUITIES, LLC$3M
- Nuveen, LLC$2M
- RHUMBLINE ADVISERS$834K
- Focus Partners Wealth$742K
- PRICE T ROWE ASSOCIATES INC /MD/$556K
Full exits 18
- Jefferies Financial Group Inc.$14M
- Patient Square Capital LP$5M
- JANE STREET GROUP, LLC$5M
- EVENTIDE ASSET MANAGEMENT, LLC$4M
- Trexquant Investment LP$4M
- BALYASNY ASSET MANAGEMENT L.P.$3M
Largest adds
- BlackRock, Inc.$41M
- STATE STREET CORP$17M
- Kynam Capital Management, LP$11M
- BANK OF AMERICA CORP /DE/$9M
- GEODE CAPITAL MANAGEMENT, LLC$8M
- WELLINGTON MANAGEMENT GROUP LLP$4M
Largest trims
- Venrock Adviser, LLC$28M
- FMR LLC$28M
- MILLENNIUM MANAGEMENT LLC$11M
- CITADEL ADVISORS LLC$10M
- VANGUARD CAPITAL MANAGEMENT LLC$9M
- SUSQUEHANNA INTERNATIONAL GROUP, LLP$8M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 32,714,937 | $123M | 15.5% | 2026-Q2 |
| Kynam Capital Management, LP added | 21,703,093 | $81M | 10.3% | 2026-Q2 |
| BlackRock, Inc. added | 17,559,822 | $66M | 8.3% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ added | 15,082,617 | $57M | 7.1% | 2026-Q2 |
| STATE STREET CORP added | 11,747,236 | $44M | 5.6% | 2026-Q2 |
| PERCEPTIVE ADVISORS LLC added | 10,439,185 | $39M | 4.9% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC trimmed | 8,525,457 | $32M | 4.0% | 2026-Q2 |
| Point72 Asset Management, L.P. trimmed | 7,811,033 | $29M | 3.7% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP added | 5,168,961 | $19M | 2.4% | 2026-Q2 |
| Venrock Adviser, LLC trimmed | 4,982,124 | $19M | 2.4% | 2026-Q2 |
| BAKER BROS. ADVISORS LP | 4,975,826 | $19M | 2.4% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 4,678,716 | $18M | 2.2% | 2026-Q2 |
| Elmind Capital, LP | 4,550,000 | $17M | 2.2% | 2026-Q2 |
| Nextech Invest Ltd. | 4,449,932 | $17M | 2.1% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 4,132,643 | $15M | 2.0% | 2026-Q2 |
| Eversept Partners, LP added | 3,558,497 | $13M | 1.7% | 2026-Q2 |
| UBS Group AG added | 3,468,359 | $13M | 1.6% | 2026-Q2 |
| Siren, L.L.C. | 3,457,711 | $13M | 1.6% | 2026-Q2 |
| ADAR1 Capital Management, LLC trimmed | 3,365,118 | $13M | 1.6% | 2026-Q2 |
| CITADEL ADVISORS LLC trimmed | 3,110,509 | $12M | 1.5% | 2026-Q2 |
| MARSHALL WACE, LLP trimmed | 3,024,351 | $11M | 1.4% | 2026-Q2 |
| Woodline Partners LP added | 2,040,210 | $8M | 1.0% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 2,003,652 | $8M | 0.9% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 1,860,290 | $7M | 0.9% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 1,824,564 | $7M | 0.9% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 1,751,167 | $7M | 0.8% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 1,685,830 | $6M | 0.8% | 2026-Q2 |
| NORTHERN TRUST CORP added | 1,675,183 | $6M | 0.8% | 2026-Q2 |
| TUDOR INVESTMENT CORP ET AL new | 1,380,687 | $5M | 0.7% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 1,267,430 | $5M | 0.6% | 2026-Q2 |
| Seven Fleet Capital Management LP added | 1,085,398 | $4M | 0.5% | 2026-Q2 |
| SPHERA FUNDS MANAGEMENT LTD. added | 879,000 | $3M | 0.4% | 2026-Q2 |
| Ally Bridge Group (NY) LLC trimmed | 775,000 | $3M | 0.4% | 2026-Q2 |
| DV EQUITIES, LLC new | 714,000 | $3M | 0.3% | 2026-Q2 |
| GILDER GAGNON HOWE & CO LLC trimmed | 704,423 | $3M | 0.3% | 2026-Q2 |
| Bank of New York Mellon Corp added | 684,539 | $3M | 0.3% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 663,038 | $2M | 0.3% | 2026-Q2 |
| FIRST TRUST ADVISORS LP added | 599,696 | $2M | 0.3% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 549,875 | $2M | 0.3% | 2026-Q2 |
| Ensign Peak Advisors, Inc trimmed | 505,055 | $2M | 0.2% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC added | 484,222 | $2M | 0.2% | 2026-Q2 |
| SCHULHOFF & CO INC | 477,550 | $2M | 0.2% | 2026-Q2 |
| Exome Asset Management LLC trimmed | 460,067 | $2M | 0.2% | 2026-Q2 |
| Nuveen, LLC new | 448,041 | $2M | 0.2% | 2026-Q2 |
| DAFNA Capital Management LLC added | 438,407 | $2M | 0.2% | 2026-Q2 |
| Assenagon Asset Management S.A. | 364,173 | $1M | 0.2% | 2026-Q2 |
| Jump Financial, LLC added | 347,400 | $1M | 0.2% | 2026-Q2 |
| Swiss National Bank added | 325,400 | $1M | 0.2% | 2026-Q2 |
| Caption Management, LLC trimmed | 300,000 | $1M | 0.1% | 2026-Q2 |
| CITIGROUP INC added | 287,866 | $1M | 0.1% | 2026-Q2 |
| LMR Partners LLP added | 273,213 | $1M | 0.1% | 2026-Q2 |
| Tidal Investments LLC added | 246,697 | $925K | 0.1% | 2026-Q2 |
| Tema ETFs LLC added | 228,987 | $859K | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS new | 222,514 | $834K | 0.1% | 2026-Q2 |
| Rafferty Asset Management, LLC trimmed | 221,377 | $830K | 0.1% | 2026-Q2 |
| Invesco Ltd. added | 220,205 | $826K | 0.1% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 219,779 | $824K | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 208,477 | $782K | 0.1% | 2026-Q2 |
| Stonepine Capital Management, LLC added | 205,000 | $769K | 0.1% | 2026-Q2 |
| Focus Partners Wealth new | 197,878 | $742K | 0.1% | 2026-Q2 |
| MORGAN STANLEY trimmed | 190,799 | $715K | 0.1% | 2026-Q2 |
| Verdad Advisers, LP added | 176,407 | $662K | 0.1% | 2026-Q2 |
| LPL Financial LLC added | 171,733 | $644K | 0.1% | 2026-Q2 |
| HighVista Strategies LLC trimmed | 169,831 | $637K | 0.1% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 163,183 | $612K | 0.1% | 2026-Q2 |
| AWM Investment Company, Inc. | 150,000 | $562K | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ new | 148,107 | $556K | 0.1% | 2026-Q2 |
| CANADA PENSION PLAN INVESTMENT BOARD added | 141,500 | $531K | 0.1% | 2026-Q2 |
| Walleye Capital LLC new | 126,526 | $474K | 0.1% | 2026-Q2 |
| BARCLAYS PLC trimmed | 126,415 | $474K | 0.1% | 2026-Q2 |
| NLB Skladi, upravljanje premozenja, d.o.o. added | 125,000 | $469K | 0.1% | 2026-Q2 |
| Legal & General Group Plc trimmed | 123,313 | $462K | 0.1% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd | 122,893 | $461K | 0.1% | 2026-Q2 |
| Velan Capital Investment Management LP trimmed | 120,000 | $450K | 0.1% | 2026-Q2 |
| Squarepoint Ops LLC trimmed | 112,152 | $421K | 0.1% | 2026-Q2 |
| PROFUND ADVISORS LLC added | 111,378 | $418K | 0.1% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 109,413 | $409K | 0.1% | 2026-Q2 |
| Virtus Investment Advisers, LLC added | 108,703 | $408K | 0.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 107,334 | $402K | 0.1% | 2026-Q2 |
| ALPS ADVISORS INC added | 107,100 | $402K | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC new | 104,635 | $392K | 0.0% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. new | 104,310 | $490K | 0.1% | 2026-Q2 |
| Aspire Growth Partners LLC | 102,254 | $383K | 0.0% | 2026-Q2 |
| Robertson Stephens Wealth Management, LLC new | 96,000 | $360K | 0.0% | 2026-Q2 |
| LANDSCAPE CAPITAL MANAGEMENT, L.L.C. | 94,240 | $353K | 0.0% | 2026-Q2 |
| ALGERT GLOBAL LLC added | 90,900 | $341K | 0.0% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 90,673 | $340K | 0.0% | 2026-Q2 |
| Miller Financial Services LLC added | 85,000 | $319K | 0.0% | 2026-Q2 |
| Engineers Gate Manager LP added | 83,130 | $312K | 0.0% | 2026-Q2 |
| Zurcher Kantonalbank (Zurich Cantonalbank) added | 79,816 | $299K | 0.0% | 2026-Q2 |
| Vanguard Global Advisers, LLC | 71,617 | $269K | 0.0% | 2026-Q2 |
| China Universal Asset Management Co., Ltd. added | 64,647 | $242K | 0.0% | 2026-Q2 |
| State of Wyoming added | 54,987 | $206K | 0.0% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC new | 54,899 | $206K | 0.0% | 2026-Q2 |
| Private Advisor Group, LLC added | 54,502 | $204K | 0.0% | 2026-Q2 |
| Merit Financial Group, LLC added | 53,503 | $201K | 0.0% | 2026-Q2 |
| Police & Firemen's Retirement System of New Jersey new | 52,499 | $197K | 0.0% | 2026-Q2 |
| State of New Jersey Common Pension Fund D added | 52,424 | $197K | 0.0% | 2026-Q2 |
| Universal- Beteiligungs- und Servicegesellschaft mbH added | 50,529 | $189K | 0.0% | 2026-Q2 |
| Congress Park Capital LLC | 49,171 | $184K | 0.0% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.