Who owns CTMX (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-Q1 13F filings. 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
The tracked-fund tape on CTMX is one-sided between 2025-Q4 and 2026-Q1: 72 added or opened and 22 trimmed or exited — on balance accumulating.
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 gap the other way — the median holder sizes CTMX more heavily than its largest holder by dollar value does.
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 2025-Q4 and 2026-Q1, across 179 tracked filers holding CTMX, 136 increased or opened the position and 48 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
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 2025-Q4 and 2026-Q1 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 34
- VANGUARD CAPITAL MANAGEMENT LLC$41M
- Nextech Invest, Ltd.$21M
- Siren, L.L.C.$16M
- WELLINGTON MANAGEMENT GROUP LLP$16M
- GILDER GAGNON HOWE & CO LLC$5M
- VANGUARD FIDUCIARY TRUST CO$5M
Full exits 9
- Commodore Capital LP$33M
- VANGUARD GROUP INC$32M
- Financial Engines Advisors L.L.C.$16M
- ORBIMED ADVISORS LLC$15M
- Ikarian Capital, LLC$14M
- Vivo Capital, LLC$12M
Largest adds
- FMR LLC$45M
- BANK OF AMERICA CORP /DE/$44M
- Kynam Capital Management, LP$32M
- CITADEL ADVISORS LLC$24M
- Elmind Capital, LP$18M
- MILLENNIUM MANAGEMENT LLC$16M
Largest trims
- Venrock Adviser, LLC$19M
- BALYASNY ASSET MANAGEMENT L.P.$13M
- BOOTHBAY FUND MANAGEMENT, LLC$4M
- GOLDMAN SACHS GROUP INC$4M
- ACADIAN ASSET MANAGEMENT LLC$3M
- ADAR1 Capital Management, LLC$2M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 31,955,637 | $150M | 13.5% | 2026-Q1 |
| Kynam Capital Management, LP added | 15,013,093 | $71M | 6.3% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 10,202,785 | $48M | 4.3% | 2026-Q1 |
| PERCEPTIVE ADVISORS LLC added | 10,098,824 | $47M | 4.3% | 2026-Q1 |
| Venrock Adviser, LLC trimmed | 9,982,124 | $47M | 4.2% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 8,733,118 | $41M | 3.7% | 2026-Q1 |
| Point72 Asset Management, L.P. added | 7,875,390 | $37M | 3.3% | 2026-Q1 |
| STATE STREET CORP added | 5,663,408 | $27M | 2.4% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 5,406,193 | $25M | 2.3% | 2026-Q1 |
| BlackRock, Inc. added | 5,228,280 | $25M | 2.2% | 2026-Q1 |
| BAKER BROS. ADVISORS LP added | 4,975,826 | $23M | 2.1% | 2026-Q1 |
| Elmind Capital, LP added | 4,550,000 | $21M | 1.9% | 2026-Q1 |
| Nextech Invest, Ltd. new | 4,449,932 | $21M | 1.9% | 2026-Q1 |
| MARSHALL WACE, LLP added | 4,138,176 | $19M | 1.7% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 3,660,190 | $17M | 1.5% | 2026-Q1 |
| Siren, L.L.C. new | 3,457,711 | $16M | 1.5% | 2026-Q1 |
| ADAR1 Capital Management, LLC trimmed | 3,410,190 | $16M | 1.4% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP added | 3,363,255 | $16M | 1.4% | 2026-Q1 |
| Eversept Partners, LP added | 3,188,514 | $15M | 1.3% | 2026-Q1 |
| UBS Group AG added | 3,120,155 | $15M | 1.3% | 2026-Q1 |
| Jefferies Financial Group Inc. added | 3,067,864 | $14M | 1.3% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 2,710,156 | $13M | 1.1% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 2,249,583 | $11M | 1.0% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 2,066,612 | $10M | 0.9% | 2026-Q1 |
| Woodline Partners LP trimmed | 2,000,825 | $9M | 0.8% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 1,930,920 | $9M | 0.8% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 1,869,615 | $9M | 0.8% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 1,459,839 | $7M | 0.6% | 2026-Q1 |
| GILDER GAGNON HOWE & CO LLC new | 1,120,309 | $5M | 0.5% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 1,102,883 | $5M | 0.5% | 2026-Q1 |
| Patient Square Capital LP new | 1,085,790 | $5M | 0.5% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 997,510 | $5M | 0.4% | 2026-Q1 |
| Ally Bridge Group (NY) LLC new | 900,000 | $4M | 0.4% | 2026-Q1 |
| EVENTIDE ASSET MANAGEMENT, LLC new | 900,000 | $4M | 0.4% | 2026-Q1 |
| Trexquant Investment LP added | 898,767 | $4M | 0.4% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 794,755 | $4M | 0.3% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 730,844 | $3M | 0.3% | 2026-Q1 |
| DV Trading LLC new | 714,000 | $3M | 0.3% | 2026-Q1 |
| NORTHERN TRUST CORP added | 612,141 | $3M | 0.3% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 606,275 | $3M | 0.3% | 2026-Q1 |
| Ensign Peak Advisors, Inc new | 592,473 | $3M | 0.3% | 2026-Q1 |
| Caption Management, LLC new | 573,224 | $3M | 0.2% | 2026-Q1 |
| FIRST TRUST ADVISORS LP added | 568,562 | $3M | 0.2% | 2026-Q1 |
| Informed Momentum Co LLC added | 565,113 | $3M | 0.2% | 2026-Q1 |
| Longaeva Partners L.P. new | 550,000 | $3M | 0.2% | 2026-Q1 |
| Velan Capital Investment Management LP added | 540,000 | $3M | 0.2% | 2026-Q1 |
| Exome Asset Management LLC trimmed | 521,468 | $2M | 0.2% | 2026-Q1 |
| MORGAN STANLEY added | 520,495 | $2M | 0.2% | 2026-Q1 |
| SCHULHOFF & CO INC added | 477,550 | $2M | 0.2% | 2026-Q1 |
| DEUTSCHE BANK AG\ added | 463,421 | $2M | 0.2% | 2026-Q1 |
| 683 Capital Management, LLC new | 425,000 | $2M | 0.2% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC added | 380,160 | $2M | 0.2% | 2026-Q1 |
| Seven Fleet Capital Management LP added | 371,398 | $2M | 0.2% | 2026-Q1 |
| Assenagon Asset Management S.A. trimmed | 364,173 | $2M | 0.2% | 2026-Q1 |
| SEVEN GRAND MANAGERS, LLC new | 325,000 | $2M | 0.1% | 2026-Q1 |
| Swiss National Bank added | 319,600 | $2M | 0.1% | 2026-Q1 |
| Soleus Capital Management, L.P. trimmed | 300,000 | $1M | 0.1% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 289,868 | $1M | 0.1% | 2026-Q1 |
| HighVista Strategies LLC added | 288,057 | $1M | 0.1% | 2026-Q1 |
| Brevan Howard Capital Management LP added | 269,202 | $1M | 0.1% | 2026-Q1 |
| SIMPLEX TRADING, LLC added | 248,438 | $1M | 0.1% | 2026-Q1 |
| SEI INVESTMENTS CO added | 248,248 | $1M | 0.1% | 2026-Q1 |
| Tidal Investments LLC added | 245,768 | $1M | 0.1% | 2026-Q1 |
| Squarepoint Ops LLC added | 241,215 | $1M | 0.1% | 2026-Q1 |
| Rafferty Asset Management, LLC trimmed | 239,824 | $1M | 0.1% | 2026-Q1 |
| LMR Partners LLP added | 234,931 | $1M | 0.1% | 2026-Q1 |
| Scientech Research LLC new | 230,598 | $1M | 0.1% | 2026-Q1 |
| DAFNA Capital Management LLC added | 230,000 | $1M | 0.1% | 2026-Q1 |
| Tema ETFs LLC new | 227,505 | $1M | 0.1% | 2026-Q1 |
| Burkehill Global Management, LP new | 225,000 | $1M | 0.1% | 2026-Q1 |
| SPHERA FUNDS MANAGEMENT LTD. trimmed | 220,000 | $1M | 0.1% | 2026-Q1 |
| Stonepine Capital Management, LLC added | 200,000 | $940K | 0.1% | 2026-Q1 |
| Centiva Capital, LP new | 200,000 | $940K | 0.1% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 189,400 | $890K | 0.1% | 2026-Q1 |
| Y-Intercept (Hong Kong) Ltd added | 167,514 | $787K | 0.1% | 2026-Q1 |
| GROUP ONE TRADING LLC added | 154,134 | $724K | 0.1% | 2026-Q1 |
| AWM Investment Company, Inc. new | 150,000 | $705K | 0.1% | 2026-Q1 |
| BARCLAYS PLC trimmed | 142,412 | $669K | 0.1% | 2026-Q1 |
| Legal & General Group Plc added | 141,893 | $667K | 0.1% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 128,796 | $605K | 0.1% | 2026-Q1 |
| TANG CAPITAL MANAGEMENT LLC | 11,065,662 | $35M | 3.2% | 2025-Q3 stale |
| Commodore Capital LP | 7,692,300 | $33M | 2.9% | 2025-Q4 stale |
| VANGUARD GROUP INC trimmed | 7,607,183 | $32M | 2.9% | 2025-Q4 stale |
| Financial Engines Advisors L.L.C. added | 3,828,717 | $16M | 1.5% | 2025-Q4 stale |
| ORBIMED ADVISORS LLC trimmed | 3,525,650 | $15M | 1.4% | 2025-Q4 stale |
| Ikarian Capital, LLC trimmed | 3,172,616 | $14M | 1.2% | 2025-Q4 stale |
| FRANKLIN RESOURCES INC added | 5,769,230 | $13M | 1.2% | 2025-Q2 stale |
| Vivo Capital, LLC | 2,884,615 | $12M | 1.1% | 2025-Q4 stale |
| RTW INVESTMENTS, LP | 3,461,500 | $11M | 1.0% | 2025-Q3 stale |
| Fairmount Funds Management LLC new | 3,896,582 | $9M | 0.8% | 2025-Q2 stale |
| RA CAPITAL MANAGEMENT, L.P. | 2,661,331 | $8M | 0.8% | 2025-Q3 stale |
| RENAISSANCE TECHNOLOGIES LLC added | 2,545,260 | $8M | 0.7% | 2025-Q3 stale |
| STEMPOINT CAPITAL LP new | 1,036,311 | $4M | 0.4% | 2025-Q4 stale |
| BVF INC/IL | 5,228,461 | $3M | 0.3% | 2025-Q1 stale |
| READYSTATE ASSET MANAGEMENT LP new | 844,643 | $2M | 0.2% | 2025-Q2 stale |
| Prosight Management, LP trimmed | 564,800 | $2M | 0.2% | 2025-Q3 stale |
| SILVERARC CAPITAL MANAGEMENT, LLC new | 385,974 | $2M | 0.1% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 335,524 | $1M | 0.1% | 2025-Q4 stale |
| Laurion Capital Management LP added | 1,293,686 | $823K | 0.1% | 2025-Q1 stale |
| Precision Wealth Strategies, LLC new | 237,081 | $756K | 0.1% | 2025-Q3 stale |
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.