ZYMEWORKS INC ZYME
COM · Common Stock · CUSIP 98985Y108 · ISIN US98985Y1082
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersMiddletown, DE
- Founded2003
- Websitezymeworks.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 ($822.3k this quarter). Holder counts are more reliable. Implied quarter-end price ≈ $25.04. Options: 8 managers hold calls ($11.4m notional), 5 hold puts ($1.6m).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 1 |
| Q4 2022 | 94 |
| Q1 2023 | 117 |
| Q2 2023 | 138 |
| Q3 2023 | 141 |
| Q4 2023 | 158 |
| Q1 2024 | 172 |
| Q2 2024 | 165 |
| Q3 2024 | 164 |
| Q4 2024 | 174 |
| Q1 2025 | 186 |
| Q2 2025 | 182 |
| Q3 2025 | 183 |
| Q4 2025 | 209 |
| Q1 2026 | 212 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 79 | 82 |
| Q3 2024 | 65 | 77 |
| Q4 2024 | 70 | 81 |
| Q1 2025 | 89 | 79 |
| Q2 2025 | 89 | 84 |
| Q3 2025 | 85 | 86 |
| Q4 2025 | 109 | 80 |
| Q1 2026 | 110 | 93 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $4.2m | $883.0k | 0.21 |
| Q3 2025 | $9.2m | $4.2m | 0.46 |
| Q4 2025 | $15.2m | $5.9m | 0.39 |
| Q1 2026 | $11.4m | $1.6m | 0.14 |
Biggest buyers
| Rubric Capital Management LP | Added | +1.2m |
| CITADEL ADVISORS LLC | Added | +894.7k |
| MPM BIOIMPACT LLC | New | +565.2k |
| ROYCE & ASSOCIATES LP | New | +299.2k |
| PERCEPTIVE ADVISORS LLC | Added | +248.2k |
| GOLDMAN SACHS GROUP INC | Added | +179.3k |
| JANE STREET GROUP, LLC | Added | +156.5k |
| BANK OF AMERICA CORP /DE/ | Added | +147.2k |
| DIADEMA PARTNERS LP | New | +142.1k |
| PANAGORA ASSET MANAGEMENT INC | Added | +128.5k |
Biggest sellers
| Siren, L.L.C. | Sold out | -1.7m |
| Vestal Point Capital, LP | Sold out | -865.0k |
| DEUTSCHE BANK AG\ | Reduced | -674.6k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Sold out | -663.5k |
| ALGERT GLOBAL LLC | Sold out | -423.6k |
| MILLENNIUM MANAGEMENT LLC | Sold out | -381.6k |
| Schonfeld Strategic Advisors LLC | Sold out | -288.6k |
| RENAISSANCE TECHNOLOGIES LLC | Sold out | -220.9k |
| BVF INC/IL | Reduced | -204.5k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | -151.7k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $5.4m216.4k shares |
| CITADEL ADVISORS LLC | Added | $2.2m87.1k shares |
| DLD Asset Management, LP | Reduced | $1.3m53.0k shares |
| MILLENNIUM MANAGEMENT LLC | New | $1.3m50.0k shares |
| Walleye Capital LLC | Unchanged | $608.5k24.3k shares |
| Walleye Trading LLC | Unchanged | $353.1k14.1k shares |
| SIMPLEX TRADING, LLC | Reduced | $135.2k5.4k shares |
| GROUP ONE TRADING LLC | Reduced | $95.2k3.8k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $853.9k34.1k shares |
| CITADEL ADVISORS LLC | Reduced | $335.5k13.4k shares |
| Walleye Trading LLC | Unchanged | $222.9k8.9k shares |
| SIMPLEX TRADING, LLC | Reduced | $215.3k8.6k shares |
| Walleye Capital LLC | Unchanged | $5.0k200 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 |
|---|---|
EcoR1 Capital, LLC
13D · may seek influence
no change · filed 2025-11-19
Stated purposeScott Platshon, one of EcoR1's employees, resigned from the Issuer's board of directors as of November 16, 2025. Concurrently with his resignation, Mr. Platshon was appointed as the Issuer's Acting Chief Investment Officer. Oleg Nodelman, the manager of EcoR1, is a member of the Issuer's board of directors. The reporting persons acquired the Stock for investment purposes based on their belief that the Issuer's Common Stock, when purchased, was undervalued and represented an attractive investment opportunity. The reporting persons will routinely monitor the Issuer regarding a wide variety of factors that affect their investment considerations, including, current and anticipated future trading prices of the Common Stock and other securities, the Issuer's operations, assets, prospects, fi… Full filing |
30.7% |
| Rubric Capital Management LP 13G · institution +1.8 pts · filed 2026-05-15 | 9.5% |
| PERCEPTIVE ADVISORS LLC 13G · passive investor new · filed 2026-04-15 | 5.4% |
| BIOTECHNOLOGY VALUE FUND L P 13G · passive investor filed 2025-11-14 | 5.2% |
Fell to 5% or below in the last year: MORGAN STANLEY (3.4%, 2026-02-12)
Insider purchases and sales in Q1 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 |
|---|---|---|---|---|---|
| Q2 2024 | 0 | — | 0 | — | — |
| Q3 2024 | 0 | — | 0 | — | — |
| Q4 2024 | 1 | $22.4m | 0 | — | — |
| Q1 2025 | 2 | $28.5m | 3 | $1.3m | — |
| Q2 2025 | 1 | $7.2m | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 1 | $1.3m | — |
| Q1 2026 | 0 | — | 4 | $3.4m | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-01-12 | Galbraith Kenneth Chair & CEO, director | Sold | $689.7k30.4k shares |
| 2026-01-12 | Moore Paul Andrew Chief Scientific Officer | Sold | $216.7k9.6k shares |
| 2026-01-12 | Smith Jeffrey T L EVP & Chief Medical Officer | Sold | $211.1k9.3k shares |
| 2026-01-12 | Hollywood Mark EVP & Chief Operating Officer | Sold | $138.7k6.1k shares |
| 2026-01-05 | Galbraith Kenneth Chair & CEO, director | Sold | $1.4m54.3k shares |
| 2026-01-05 | Moore Paul Andrew Chief Scientific Officer | Sold | $504.8k20.1k shares |
| 2026-01-05 | Smith Jeffrey T L EVP & Chief Medical Officer | Sold | $264.5k10.5k 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, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| EcoR1 Capital, LLC 24.58% of their portfolio | 23.0m $575.2m | Unchanged |
| Rubric Capital Management LP 2.15% of their portfolio | 7.0m $175.3m | Added +1.2m |
| BlackRock, Inc. 0.00% of their portfolio | 4.6m $114.0m | Reduced -41.7k |
| BVF INC/IL 2.98% of their portfolio | 3.7m $93.5m | Reduced -204.5k |
| PERCEPTIVE ADVISORS LLC 1.74% of their portfolio | 3.5m $87.9m | Added +248.2k |
| MORGAN STANLEY 0.00% of their portfolio | 2.5m $62.1m | Reduced -112.5k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.06% of their portfolio | 1.9m $47.8m | Added +86.0k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 1.7m $42.7m | First filing |
| CITADEL ADVISORS LLC 0.02% of their portfolio | 1.2m $28.8m | Added +894.7k |
| DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio | 1.1m $28.5m | Reduced -20.1k |
| Nextech Invest Ltd. 1.96% of their portfolio | 1.1m $27.9m | Unchanged |
| STATE STREET CORP 0.00% of their portfolio | 1.0m $25.3m | Reduced -25.9k |
| Capricorn Fund Managers Ltd 3.93% of their portfolio | 1.0m $25.2m | Reduced -15.6k |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 921.2k $23.1m | Reduced -674.6k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.01% of their portfolio | 743.9k $18.6m | Added +43.9k |
| Assenagon Asset Management S.A. 0.03% of their portfolio | 728.0k $18.2m | Added +80.6k |
| FMR LLC 0.00% of their portfolio | 667.2k $16.7m | Added +107.1k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 659.9k $16.5m | Added +12.0k |
| Nuveen, LLC 0.00% of their portfolio | 651.7k $16.3m | Added +3.3k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 599.5k $15.0m | Added +179.3k |
| MPM BIOIMPACT LLC 1.09% of their portfolio | 565.2k $14.2m | New |
| Prosight Management, LP 2.21% of their portfolio | 539.0k $13.5m | Added +8.7k |
| Qube Research & Technologies Ltd 0.02% of their portfolio | 511.9k $12.8m | Added +37.6k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 499.9k $12.5m | First filing |
| Redmile Group, LLC 0.82% of their portfolio | 491.7k $12.3m | Unchanged |
| Hillsdale Investment Management Inc. 0.24% of their portfolio | 345.6k $8.7m | Added +107.7k |
| SummitTX Capital, L.P. 0.26% of their portfolio | 321.4k $8.0m | Added +97.2k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 320.2k $8.0m | Added +12.2k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 319.4k $8.0m | Reduced -876 |
| ROYCE & ASSOCIATES LP 0.07% of their portfolio | 299.2k $7.5m | New |
| PICTON MAHONEY ASSET MANAGEMENT 0.07% of their portfolio | 256.7k $6.4m | Added +11.9k |
| Granahan Investment Management, LLC 0.30% of their portfolio | 250.8k $6.3m | Added +26.4k |
| HRT FINANCIAL LP 0.02% of their portfolio | 237.9k $6.0m | Added +116.8k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 236.8k $5.9m | Added +147.2k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 235.6k $5.9m | Added +11.8k |
| JANE STREET GROUP, LLC 0.01% of their portfolio | 227.0k $5.7m | Added +156.5k |
| PANAGORA ASSET MANAGEMENT INC 0.02% of their portfolio | 206.9k $5.2m | Added +128.5k |
| Man Group plc 0.01% of their portfolio | 189.9k $4.8m | Added +114.6k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 189.6k $4.7m | Reduced -18.7k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 185.1k $4.6m | Reduced -35.8k |
| FEDERATED HERMES, INC. 0.01% of their portfolio | 182.4k $4.6m | Added +29.7k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 176.4k $4.4m | Reduced -11.3k |
| UBS Group AG 0.00% of their portfolio | 171.8k $4.3m | Reduced -107.1k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.03% of their portfolio | 163.6k $4.1m | Reduced -18.1k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.08% of their portfolio | 148.2k $3.7m | Added +2.7k |
| XTX Topco Ltd 0.06% of their portfolio | 143.9k $3.6m | Added +50.4k |
| DIADEMA PARTNERS LP 1.47% of their portfolio | 142.1k $3.6m | New |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 138.7k $3.5m | Reduced -43.0k |
| Invesco Ltd. 0.00% of their portfolio | 125.6k $3.1m | Reduced -131.9k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 124.1k $3.1m | Reduced -4.0k |
| CITIGROUP INC 0.00% of their portfolio | 114.3k $2.9m | Added +3.1k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 114.1k $2.8m | Added +79.1k |
| PLATINUM INVESTMENT MANAGEMENT LTD 0.66% of their portfolio | 105.2k $2.6m | Unchanged |
| Tidal Investments LLC 0.01% of their portfolio | 104.9k $2.6m | New |
| Tema ETFs LLC 0.18% of their portfolio | 104.9k $2.6m | Added +29.0k |
| Fisher Asset Management, LLC 0.00% of their portfolio | 101.4k $2.5m | Added +33.2k |
| Susquehanna Portfolio Strategies, LLC 0.04% of their portfolio | 99.8k $2.5m | Unchanged |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 90.7k $2.3m | Reduced -406 |
| KORNITZER CAPITAL MANAGEMENT INC /KS 0.05% of their portfolio | 88.8k $2.2m | Unchanged |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 84.4k $2.1m | First filing |
| Squarepoint Ops LLC 0.00% of their portfolio | 83.1k $2.1m | New |
| MACKENZIE FINANCIAL CORP 0.00% of their portfolio | 82.7k $2.1m | Added +37.3k |
| Verdad Advisers, LP 2.33% of their portfolio | 82.7k $2.1m | New |
| PRINCIPAL FINANCIAL GROUP INC 0.00% of their portfolio | 78.5k $2.0m | New |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 77.7k $1.9m | Added +18.7k |
| STIFEL FINANCIAL CORP 0.00% of their portfolio | 76.8k $1.9m | Added +909 |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 75.4k $1.9m | Reduced -99 |
| CREDIT AGRICOLE S A 0.01% of their portfolio | 75.0k $1.9m | Unchanged |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 74.2k $1.9m | Reduced -38.9k |
| Swiss National Bank 0.00% of their portfolio | 74.2k $1.9m | Unchanged |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 70.9k $1.8m | Added +12.0k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 66.1k $1.7m | Reduced -9.5k |
| Dana Investment Advisors, Inc. 0.04% of their portfolio | 56.1k $1.4m | Added +7.8k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 55.9k $1.5m | Added +5.9k |
| Campbell & CO Investment Adviser LLC 0.08% of their portfolio | 54.9k $1.4m | Added +21.3k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 47.5k $1.2m | Reduced -10.9k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 47.4k $1.2m | Reduced -7.7k |
| North Growth Management Ltd. 0.17% of their portfolio | 46.0k $1.1m | Added +1.0k |
| SEGALL BRYANT & HAMILL, LLC 0.02% of their portfolio | 45.7k $1.1m | New |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.00% of their portfolio | 42.8k $1.1m | New |
| VICTORY CAPITAL MANAGEMENT INC 0.00% of their portfolio | 42.4k $1.1m | Reduced -501 |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 40.4k $1.0m | Reduced -393 |
| Manatuck Hill Partners, LLC 0.33% of their portfolio | 40.0k $1.0m | New |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 39.8k $995.3k | Added +39.4k |
| Quantinno Capital Management LP 0.00% of their portfolio | 39.6k $992.6k | Added +10.8k |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 39.4k $985.4k | Added +18.9k |
| Connor, Clark & Lunn Investment Management Ltd. 0.00% of their portfolio | 37.9k $949.5k | New |
| HSBC HOLDINGS PLC 0.00% of their portfolio | 37.8k $940.1k | Added +2.0k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 37.4k $936.2k | Reduced -372 |
| O'SHAUGHNESSY ASSET MANAGEMENT, LLC 0.00% of their portfolio | 37.1k $929.7k | Reduced -5.9k |
| TUDOR INVESTMENT CORP ET AL 0.00% of their portfolio | 36.9k $923.4k | Added +6.6k |
| HighTower Advisors, LLC 0.00% of their portfolio | 36.3k $908.0k | New |
| Persistent Asset Partners Ltd 0.35% of their portfolio | 35.9k $899.8k | Added +28.6k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 35.5k $889.0k | Added +6.7k |
| HighVista Strategies LLC 0.24% of their portfolio | 34.1k $853.5k | New |
| MARTINGALE ASSET MANAGEMENT L P 0.02% of their portfolio | 32.8k $820.4k | New |
| Creative Planning 0.00% of their portfolio | 32.4k $811.1k | Added +4.1k |
| MARSHALL WACE, LLP 0.00% of their portfolio | 32.2k $806.9k | New |
| SBI Okasan Asset Management Co.Ltd. 0.03% of their portfolio | 32.0k $774.7k | Unchanged |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 31.6k $791.1k | Added +14.2k |