CYTOMX THERAPEUTICS INC CTMX
COM · Common Stock · CUSIP 23284F105 · ISIN US23284F1057
Company in South San Francisco, United States
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersSouth San Francisco, CA
- Founded2008
- Websitecytomx.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($36.9k this quarter). Holder counts are more reliable. Shares outstanding: 217.9m as of 2026-07-31, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $3.75. Options: 7 managers hold calls ($5.3m notional), 5 hold puts ($2.6m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 85 |
| Q4 2022 | 81 |
| Q1 2023 | 77 |
| Q2 2023 | 68 |
| Q3 2023 | 63 |
| Q4 2023 | 69 |
| Q1 2024 | 89 |
| Q2 2024 | 75 |
| Q3 2024 | 70 |
| Q4 2024 | 71 |
| Q1 2025 | 67 |
| Q2 2025 | 84 |
| Q3 2025 | 103 |
| Q4 2025 | 122 |
| Q1 2026 | 179 |
| Q2 2026 | 179 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 27 | 36 |
| Q4 2024 | 32 | 31 |
| Q1 2025 | 27 | 36 |
| Q2 2025 | 56 | 29 |
| Q3 2025 | 61 | 37 |
| Q4 2025 | 71 | 46 |
| Q1 2026 | 128 | 47 |
| Q2 2026 | 115 | 78 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $6.8m | $1.0m | 0.15 |
| Q4 2025 | $6.1m | $359.5k | 0.06 |
| Q1 2026 | $13.3m | $12.7m | 0.95 |
| Q2 2026 | $5.3m | $2.6m | 0.49 |
Biggest buyers
| BlackRock, Inc. | Added | +12.3m |
| Kynam Capital Management, LP | Added | +6.7m |
| STATE STREET CORP | Added | +6.1m |
| BANK OF AMERICA CORP /DE/ | Added | +4.9m |
| GEODE CAPITAL MANAGEMENT, LLC | Added | +2.6m |
| WELLINGTON MANAGEMENT GROUP LLP | Added | +1.6m |
| TWO SIGMA INVESTMENTS, LP | Added | +1.4m |
| TUDOR INVESTMENT CORP ET AL | New | +1.4m |
| NORTHERN TRUST CORP | Added | +1.1m |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Added | +956.4k |
Biggest sellers
| Venrock Adviser, LLC | Reduced | -5.0m |
| Jefferies Financial Group Inc. | Sold out | -3.1m |
| CITADEL ADVISORS LLC | Reduced | -2.3m |
| MILLENNIUM MANAGEMENT LLC | Reduced | -2.0m |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | -1.8m |
| MARSHALL WACE, LLP | Reduced | -1.1m |
| Patient Square Capital LP | Sold out | -1.1m |
| JANE STREET GROUP, LLC | Sold out | -997.5k |
| EVENTIDE ASSET MANAGEMENT, LLC | Sold out | -900.0k |
| Trexquant Investment LP | Sold out | -898.8k |
Biggest calls
| Caption Management, LLC | Reduced | $2.6m700.0k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $1.4m372.0k shares |
| CITADEL ADVISORS LLC | Reduced | $491.2k131.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $267.0k71.2k shares |
| GROUP ONE TRADING LLC | Reduced | $263.2k70.2k shares |
| TUDOR INVESTMENT CORP ET AL | New | $188.6k50.3k shares |
| JANE STREET GROUP, LLC | Reduced | $37.9k10.1k shares |
Biggest puts
| Caption Management, LLC | Unchanged | $1.6m420.0k shares |
| CITADEL ADVISORS LLC | Reduced | $332.2k88.6k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $307.1k81.9k shares |
| GROUP ONE TRADING LLC | Reduced | $235.1k62.7k shares |
| SIMPLEX TRADING, LLC | Reduced | $116.6k31.1k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution +2.2 pts · filed 2026-02-05 | 14.6% |
| Kynam Capital Management, LP 13G · institution +3.1 pts · filed 2026-08-14 | 10.0% |
| BlackRock, Inc. 13G · institution new · filed 2026-07-27 | 7.6% |
| Longitude Capital Partners V, LLC 13G · passive investor -0.3 pts · filed 2026-05-15 | 7.0% |
| BANK OF AMERICA CORP /DE/ 13G · institution -1.6 pts · filed 2026-10-28 | 5.4% |
| STATE STREET CORP 13G · institution new · filed 2026-08-07 | 5.4% |
Fell to 5% or below in the last year: Point72 Asset Management, L.P. (3.6%, 2026-08-14), Venrock Healthcare Capital Partners III, L.P. (4.6%, 2026-05-15), Seven Fleet Capital Management LP (0.5%, 2026-05-15), PERCEPTIVE ADVISORS LLC (4.6%, 2026-05-15), VANGUARD GROUP INC (0.0%, 2026-03-26), TANG CAPITAL MANAGEMENT LLC (0.0%, 2026-02-17), ORBIMED ADVISORS LLC (2.1%, 2026-02-17)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 5 | $48.0k | — |
| Q2 2025 | 0 | — | 3 | $220.1k | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 1 | $462.1k | $462.1k |
| Q1 2026 | 0 | — | 4 | $1.2m | $763.8k |
| Q2 2026 | 0 | — | 1 | $5.0k | — |
| Q3 2026 | 0 | — | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-06-15 | Ogden Christopher Chief Financial Officer | Sold | $5.0k1.6k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.01% of their portfolio | 32.7m $122.7m | Added +759.3k |
| Kynam Capital Management, LP 4.50% of their portfolio | 21.7m $81.4m | Added +6.7m |
| BlackRock, Inc. 0.00% of their portfolio | 17.6m $65.8m | Added +12.3m |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 15.1m $56.6m | Added +4.9m |
| STATE STREET CORP 0.00% of their portfolio | 11.7m $44.1m | Added +6.1m |
| PERCEPTIVE ADVISORS LLC 0.61% of their portfolio | 10.4m $39.1m | Added +340.4k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 8.5m $32.0m | Reduced -207.7k |
| Point72 Asset Management, L.P. 0.04% of their portfolio | 7.8m $29.3m | Reduced -64.4k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 5.2m $19.4m | Added +1.6m |
| Venrock Adviser, LLC 0.57% of their portfolio | 5.0m $18.7m | Reduced -5.0m |
| BAKER BROS. ADVISORS LP 0.09% of their portfolio | 5.0m $18.7m | Unchanged |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 4.7m $17.5m | Added +2.6m |
| Elmind Capital, LP 4.29% of their portfolio | 4.5m $17.1m | Unchanged |
| Nextech Invest Ltd. 0.79% of their portfolio | 4.4m $16.7m | Unchanged |
| TWO SIGMA INVESTMENTS, LP 0.01% of their portfolio | 4.1m $15.5m | Added +1.4m |
| Eversept Partners, LP 0.73% of their portfolio | 3.6m $13.3m | Added +370.0k |
| UBS Group AG 0.00% of their portfolio | 3.5m $13.0m | Added +348.2k |
| Siren, L.L.C. 0.26% of their portfolio | 3.5m $13.0m | Unchanged |
| ADAR1 Capital Management, LLC 0.59% of their portfolio | 3.4m $12.6m | Reduced -45.1k |
| CITADEL ADVISORS LLC 0.01% of their portfolio | 3.1m $11.7m | Reduced -2.3m |
| MARSHALL WACE, LLP 0.01% of their portfolio | 3.0m $11.3m | Reduced -1.1m |
| Woodline Partners LP 0.02% of their portfolio | 2.0m $7.7m | Added +39.4k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.0m $7.5m | Added +543.8k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 1.9m $7.0m | Reduced -70.6k |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 1.8m $6.8m | Reduced -425.0k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 1.8m $6.6m | Added +956.4k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 1.7m $6.3m | Reduced -2.0m |
| NORTHERN TRUST CORP 0.00% of their portfolio | 1.7m $6.3m | Added +1.1m |
| TUDOR INVESTMENT CORP ET AL 0.02% of their portfolio | 1.4m $5.2m | New |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 1.3m $4.8m | Added +164.5k |
| Seven Fleet Capital Management LP 0.67% of their portfolio | 1.1m $4.1m | Unchanged |
| SPHERA FUNDS MANAGEMENT LTD. 0.47% of their portfolio | 879.0k $3.3m | Added +659.0k |
| Ally Bridge Group (NY) LLC 3.75% of their portfolio | 775.0k $2.9m | Reduced -125.0k |
| Assenagon Asset Management S.A. 0.00% of their portfolio | 728.3k $2.7m | Added +364.2k |
| DV EQUITIES, LLC 0.39% of their portfolio | 714.0k $2.7m | First filing |
| GILDER GAGNON HOWE & CO LLC 0.03% of their portfolio | 704.4k $2.6m | Reduced -415.9k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 684.5k $2.6m | Added +394.7k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 663.0k $2.5m | Added +199.6k |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 599.7k $2.2m | Added +31.1k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 549.9k $2.1m | Added +421.1k |
| Ensign Peak Advisors, Inc 0.00% of their portfolio | 505.1k $1.9m | Reduced -87.4k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 484.2k $1.8m | Added +104.1k |
| SCHULHOFF & CO INC 0.72% of their portfolio | 477.6k $1.8m | Unchanged |
| Exome Asset Management LLC 1.06% of their portfolio | 460.1k $1.7m | Reduced -61.4k |
| Nuveen, LLC 0.00% of their portfolio | 448.0k $1.7m | New |
| DAFNA Capital Management LLC 0.31% of their portfolio | 438.4k $1.6m | Added +208.4k |
| Jump Financial, LLC 0.01% of their portfolio | 347.4k $1.3m | Added +336.7k |
| Swiss National Bank 0.00% of their portfolio | 325.4k $1.2m | Added +5.8k |
| Caption Management, LLC 0.04% of their portfolio | 300.0k $1.1m | Reduced -273.2k |
| CITIGROUP INC 0.00% of their portfolio | 287.9k $1.1m | Added +186.1k |
| LMR Partners LLP 0.01% of their portfolio | 273.2k $1.0m | Added +38.3k |
| Tidal Investments LLC 0.00% of their portfolio | 246.7k $925.1k | Added +929 |
| Tema ETFs LLC 0.03% of their portfolio | 229.0k $858.7k | First filing |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 222.5k $834.4k | New |
| Rafferty Asset Management, LLC 0.00% of their portfolio | 221.4k $830.2k | Reduced -18.4k |
| Invesco Ltd. 0.00% of their portfolio | 220.2k $825.8k | Added +158.7k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 219.8k $824.2k | Added +30.4k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 208.5k $781.8k | Added +120.1k |
| Stonepine Capital Management, LLC 0.59% of their portfolio | 205.0k $768.8k | Added +5.0k |
| Focus Partners Wealth 0.00% of their portfolio | 197.9k $742.0k | New |
| MORGAN STANLEY 0.00% of their portfolio | 190.8k $715.5k | Reduced -329.7k |
| Verdad Advisers, LP 0.63% of their portfolio | 176.4k $661.5k | Added +146.2k |
| LPL Financial LLC 0.00% of their portfolio | 171.7k $644.0k | Added +49.1k |
| HighVista Strategies LLC 0.15% of their portfolio | 169.8k $636.9k | Reduced -118.2k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 163.2k $611.9k | Added +156.6k |
| AWM Investment Company, Inc. 0.05% of their portfolio | 150.0k $562.5k | Unchanged |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 148.1k $556.0k | New |
| CANADA PENSION PLAN INVESTMENT BOARD 0.00% of their portfolio | 141.5k $530.6k | Added +32.7k |
| Walleye Capital LLC 0.00% of their portfolio | 126.5k $474.5k | New |
| BARCLAYS PLC 0.00% of their portfolio | 126.4k $474.1k | Reduced -16.0k |
| NLB Skladi, upravljanje premozenja, d.o.o. 0.02% of their portfolio | 125.0k $468.8k | Added +13.9k |
| Legal & General Group Plc 0.00% of their portfolio | 123.3k $462.4k | Reduced -18.6k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 122.9k $460.8k | Unchanged |
| Velan Capital Investment Management LP 0.28% of their portfolio | 120.0k $450.0k | Reduced -420.0k |
| Squarepoint Ops LLC 0.00% of their portfolio | 112.2k $420.6k | Reduced -129.1k |
| PROFUND ADVISORS LLC 0.01% of their portfolio | 111.4k $417.7k | Added +6.8k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 109.4k $409.2k | Added +78.7k |
| Virtus Investment Advisers, LLC 0.09% of their portfolio | 108.7k $407.6k | Added +43.6k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 107.3k $402.2k | Added +90.7k |
| ALPS ADVISORS INC 0.00% of their portfolio | 107.1k $401.6k | Added +1.3k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 104.6k $392.4k | New |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 104.3k $490.3k | New |
| Aspire Growth Partners LLC 0.22% of their portfolio | 102.3k $383.5k | Unchanged |
| Robertson Stephens Wealth Management, LLC 0.01% of their portfolio | 96.0k $360.0k | New |
| LANDSCAPE CAPITAL MANAGEMENT, L.L.C. 0.02% of their portfolio | 94.2k $353.4k | Unchanged |
| ALGERT GLOBAL LLC 0.00% of their portfolio | 90.9k $340.9k | New |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 90.7k $340.0k | Reduced -1.8m |
| Miller Financial Services LLC 0.26% of their portfolio | 85.0k $318.8k | Added +13.0k |
| Engineers Gate Manager LP 0.00% of their portfolio | 83.1k $311.7k | Added +53.7k |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 79.8k $299.3k | Added +31.8k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 71.6k $268.6k | Unchanged |
| China Universal Asset Management Co., Ltd. 0.01% of their portfolio | 64.6k $242.4k | Added +9.6k |
| State of Wyoming 0.02% of their portfolio | 55.0k $206.2k | Added +2.3k |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 54.9k $205.9k | New |
| Private Advisor Group, LLC 0.00% of their portfolio | 54.5k $204.4k | Added +10.5k |
| Merit Financial Group, LLC 0.00% of their portfolio | 53.5k $200.6k | Added +260 |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 52.5k $196.9k | New |
| State of New Jersey Common Pension Fund D 0.00% of their portfolio | 52.4k $196.6k | Added +20.6k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.00% of their portfolio | 50.5k $189.5k | Added +23.9k |
| Congress Park Capital LLC 0.05% of their portfolio | 49.2k $184.4k | Unchanged |