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 ($879.0k this quarter). Holder counts are more reliable. Implied quarter-end price ≈ $26.13. Options: 4 managers hold calls ($4.8m notional), 3 hold puts ($3.5m).
Trends to Q2 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 |
| Q2 2026 | 203 |
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 | 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 |
| Q2 2026 | 83 | 101 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $9.2m | $4.2m | 0.46 |
| Q4 2025 | $15.2m | $5.9m | 0.39 |
| Q1 2026 | $11.4m | $1.6m | 0.14 |
| Q2 2026 | $4.8m | $3.5m | 0.73 |
Biggest buyers
| Assenagon Asset Management S.A. | Added | +1.8m |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. | New | +889.8k |
| PERCEPTIVE ADVISORS LLC | Added | +672.9k |
| FIRST TRUST ADVISORS LP | New | +340.4k |
| Pictet Asset Management Holding SA | Added | +298.9k |
| Prosight Management, LP | Added | +135.4k |
| STATE OF WISCONSIN INVESTMENT BOARD | Added | +89.5k |
| Granahan Investment Management, LLC | Added | +85.4k |
| Y-Intercept (Hong Kong) Ltd | New | +83.5k |
| LMR Partners LLP | New | +82.5k |
Biggest sellers
| MPM BIOIMPACT LLC | Sold out | -565.2k |
| Nuveen, LLC | Reduced | -532.3k |
| DEUTSCHE BANK AG\ | Reduced | -524.1k |
| Capricorn Fund Managers Ltd | Reduced | -520.7k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | Reduced | -325.4k |
| BlackRock, Inc. | Reduced | -302.9k |
| ROYCE & ASSOCIATES LP | Sold out | -299.2k |
| MORGAN STANLEY | Reduced | -249.3k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | Reduced | -238.0k |
| HRT FINANCIAL LP | Sold out | -237.9k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $3.4m130.4k shares |
| CITADEL ADVISORS LLC | Reduced | $1.4m52.2k shares |
| SIMPLEX TRADING, LLC | Reduced | $15.7k600 shares |
| GROUP ONE TRADING LLC | Reduced | $5.2k200 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $2.5m93.8k shares |
| SIMPLEX TRADING, LLC | Added | $1.0m39.0k shares |
| GROUP ONE TRADING LLC | New | $7.8k300 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), Redmile Group, LLC (4.9%, 2025-11-14)
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 | 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 | — |
| Q2 2026 | 0 | — | 0 | — | — |
| Q3 2026 | 0 | — | 0 | — | — |
None reported since 1 Apr 2026.
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| EcoR1 Capital, LLC 29.77% of their portfolio | 23.0m $600.4m | Unchanged |
| Rubric Capital Management LP 1.68% of their portfolio | 7.0m $183.0m | Unchanged |
| BlackRock, Inc. 0.00% of their portfolio | 4.3m $111.1m | Reduced -302.9k |
| PERCEPTIVE ADVISORS LLC 1.70% of their portfolio | 4.2m $109.3m | Added +672.9k |
| BVF INC/IL 2.44% of their portfolio | 3.6m $95.4m | Reduced -85.0k |
| Assenagon Asset Management S.A. 0.04% of their portfolio | 2.5m $65.5m | Added +1.8m |
| MORGAN STANLEY 0.00% of their portfolio | 2.2m $58.3m | Reduced -249.3k |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. 0.05% of their portfolio | 1.8m $46.6m | Reduced -126.9k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 1.6m $40.8m | Reduced -146.6k |
| Nextech Invest Ltd. 1.38% of their portfolio | 1.1m $29.1m | Unchanged |
| STATE STREET CORP 0.00% of their portfolio | 1.1m $28.4m | Added +76.4k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 995.0k $26.0m | Reduced -144.2k |
| CITADEL ADVISORS LLC 0.01% of their portfolio | 914.1k $23.9m | Reduced -235.9k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.03% of their portfolio | 889.8k $23.3m | New |
| FMR LLC 0.00% of their portfolio | 702.6k $18.4m | Added +35.4k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 692.4k $18.1m | Added +32.5k |
| Prosight Management, LP 3.04% of their portfolio | 674.4k $17.6m | Added +135.4k |
| Qube Research & Technologies Ltd 0.02% of their portfolio | 593.6k $15.5m | Added +81.7k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 510.0k $13.3m | Added +10.2k |
| Redmile Group, LLC 0.86% of their portfolio | 491.7k $12.9m | Unchanged |
| Capricorn Fund Managers Ltd 1.02% of their portfolio | 486.5k $12.7m | Reduced -520.7k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 470.8k $12.3m | Reduced -128.7k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.00% of their portfolio | 418.5k $10.9m | Reduced -325.4k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 397.2k $10.4m | Reduced -524.1k |
| Hillsdale Investment Management Inc. 0.23% of their portfolio | 382.9k $10.0m | Added +37.3k |
| FIRST TRUST ADVISORS LP 0.01% of their portfolio | 340.4k $8.9m | New |
| Granahan Investment Management, LLC 0.31% of their portfolio | 336.2k $8.8m | Added +85.4k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 321.1k $8.4m | Added +863 |
| Pictet Asset Management Holding SA 0.01% of their portfolio | 308.2k $7.4m | Added +298.9k |
| PICTON MAHONEY ASSET MANAGEMENT 0.07% of their portfolio | 271.3k $7.1m | Added +14.7k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.04% of their portfolio | 223.8k $5.8m | Added +60.1k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 219.1k $5.7m | Reduced -17.7k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 217.2k $5.7m | Added +27.6k |
| SummitTX Capital, L.P. 0.15% of their portfolio | 210.8k $5.5m | Reduced -110.6k |
| Man Group plc 0.01% of their portfolio | 210.8k $5.5m | Added +20.9k |
| FEDERATED HERMES, INC. 0.01% of their portfolio | 188.0k $4.9m | Added +5.6k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 166.4k $4.4m | Reduced -10.0k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.01% of their portfolio | 155.6k $4.1m | Added +89.5k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 152.4k $4.0m | Reduced -32.7k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.07% of their portfolio | 145.4k $3.8m | Reduced -2.8k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 144.8k $3.8m | Reduced -90.8k |
| DIADEMA PARTNERS LP 1.31% of their portfolio | 142.1k $3.7m | Unchanged |
| CITIGROUP INC 0.00% of their portfolio | 131.4k $3.4m | Added +17.1k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 131.1k $3.4m | Added +7.0k |
| XTX Topco Ltd 0.04% of their portfolio | 125.9k $3.3m | Reduced -18.0k |
| Nuveen, LLC 0.00% of their portfolio | 119.4k $3.1m | Reduced -532.3k |
| PANAGORA ASSET MANAGEMENT INC 0.01% of their portfolio | 118.6k $3.1m | Reduced -88.3k |
| UBS Group AG 0.00% of their portfolio | 115.1k $3.0m | Reduced -56.7k |
| Invesco Ltd. 0.00% of their portfolio | 112.2k $2.9m | Reduced -13.4k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 111.3k $2.9m | Added +20.6k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 110.0k $2.9m | Reduced -28.7k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 106.4k $2.6m | Reduced -7.7k |
| Tidal Investments LLC 0.01% of their portfolio | 105.6k $2.8m | Added +684 |
| Tema ETFs LLC 0.09% of their portfolio | 105.6k $2.8m | First filing |
| PLATINUM INVESTMENT MANAGEMENT LTD 0.68% of their portfolio | 105.2k $2.7m | Unchanged |
| Manatuck Hill Partners, LLC 0.87% of their portfolio | 100.0k $2.6m | Added +60.0k |
| KORNITZER CAPITAL MANAGEMENT INC /KS 0.05% of their portfolio | 88.8k $2.3m | Unchanged |
| MACKENZIE FINANCIAL CORP 0.00% of their portfolio | 87.7k $2.3m | Added +5.0k |
| PRINCIPAL FINANCIAL GROUP INC 0.00% of their portfolio | 85.0k $2.2m | Added +6.4k |
| Y-Intercept (Hong Kong) Ltd 0.04% of their portfolio | 83.5k $2.2m | New |
| LMR Partners LLP 0.02% of their portfolio | 82.5k $2.2m | New |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 82.3k $2.2m | Added +8.0k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 81.4k $2.1m | Reduced -238.0k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 80.1k $2.1m | Reduced -4.3k |
| STIFEL FINANCIAL CORP 0.00% of their portfolio | 77.2k $2.0m | Added +458 |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 76.5k $2.0m | Reduced -1.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 75.1k $2.0m | Reduced -333 |
| Swiss National Bank 0.00% of their portfolio | 74.2k $1.9m | Unchanged |
| MARTINGALE ASSET MANAGEMENT L P 0.05% of their portfolio | 73.3k $1.9m | Added +40.5k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 71.9k $1.9m | New |
| Dana Investment Advisors, Inc. 0.05% of their portfolio | 71.7k $1.9m | Added +15.6k |
| CREDIT AGRICOLE S A 0.00% of their portfolio | 71.0k $1.9m | Reduced -4.0k |
| Fisher Asset Management, LLC 0.00% of their portfolio | 70.8k $1.9m | Reduced -30.7k |
| SEGALL BRYANT & HAMILL, LLC 0.02% of their portfolio | 66.8k $1.7m | Added +21.1k |
| Verdad Advisers, LP 1.67% of their portfolio | 66.7k $1.7m | Reduced -16.0k |
| Susquehanna Portfolio Strategies, LLC 0.03% of their portfolio | 65.2k $1.7m | Reduced -34.5k |
| Campbell & CO Investment Adviser LLC 0.08% of their portfolio | 60.9k $1.6m | Added +6.0k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 56.3k $1.5m | Added +8.9k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 55.9k $1.4m | Unchanged |
| Virtus Investment Advisers, LLC 0.31% of their portfolio | 50.8k $1.3m | Added +40.1k |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 48.7k $1.3m | Added +8.3k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 47.9k $1.3m | Added +417 |
| Quantinno Capital Management LP 0.00% of their portfolio | 47.6k $1.2m | Added +8.0k |
| North Growth Management Ltd. 0.15% of their portfolio | 46.0k $1.2m | Unchanged |
| Legal & General Group Plc 0.00% of their portfolio | 43.2k $1.1m | Added +17.0k |
| VICTORY CAPITAL MANAGEMENT INC 0.00% of their portfolio | 42.5k $1.1m | Added +120 |
| MARSHALL WACE, LLP 0.00% of their portfolio | 40.9k $1.1m | Added +8.7k |
| O'SHAUGHNESSY ASSET MANAGEMENT, LLC 0.00% of their portfolio | 39.5k $1.0m | Added +2.4k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 38.5k $1.0m | Added +3.0k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 37.7k $986.6k | Added +355 |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.00% of their portfolio | 36.9k $965.1k | Reduced -5.9k |
| TUDOR INVESTMENT CORP ET AL 0.00% of their portfolio | 36.5k $953.4k | Reduced -404 |
| HighTower Advisors, LLC 0.00% of their portfolio | 36.1k $943.7k | Reduced -162 |
| Persistent Asset Partners Ltd 0.30% of their portfolio | 35.9k $939.3k | Unchanged |
| HighVista Strategies LLC 0.20% of their portfolio | 34.0k $889.1k | Reduced -72 |
| COMMONWEALTH EQUITY SERVICES, LLC 0.00% of their portfolio | 32.1k $837.8k | Added +6.0k |
| SBI Okasan Asset Management Co.Ltd. 0.03% of their portfolio | 32.0k $771.2k | Unchanged |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 30.9k $807.4k | Reduced -706 |
| Creative Planning 0.00% of their portfolio | 29.7k $777.2k | Reduced -2.7k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 27.9k $728.9k | Reduced -1.8k |