Zymeworks
Develops antibody medicines and earns royalties from partner-run therapies.
Something off on this page? Send us feedback.
Breakdown13F · Form 4
Institutions and insiders are filed separately and overlap, so together they can pass the whole company. No split is drawn from them.
Shares outstanding 73.57M · Float —
Float — provider float is below the insider stake.
The provider's float is smaller than the insider stake it should exclude, so it is not shown.
Institutions13F, as of Jun 30, 2026
208 holders · 69.47M shares · 28 new positions · 90 increased · 72 reduced · 36 closed
| Holder | Shares | % outstanding | Chg q/q | Filed |
|---|---|---|---|---|
| Ecor1 Capital, LLC | 22.97M | 31.22% | 0 | Aug 14, 2026 |
| Rubric Capital Management LP | 7.00M | 9.51% | 0 | Aug 14, 2026 |
| BlackRock, Inc. | 4.25M | 5.78% | −302.9K | Aug 7, 2026 |
| Perceptive Advisors LLC | 4.18M | 5.69% | +672.9K | Aug 14, 2026 |
| BVF Inc/IL | 3.65M | 4.96% | −85.0K | Aug 14, 2026 |
| Morgan Stanley | 2.23M | 3.03% | −249.3K | Aug 13, 2026 |
| BNP Paribas Asset Management Holding S.A. | 1.78M | 2.42% | −126.9K | Aug 13, 2026 |
| Vanguard Capital Management LLC | 1.56M | 2.12% | −146.6K | Aug 13, 2026 |
Beneficial owners13D/G · 5% or more, as filed
| Holder | % of class | Shares | Form | Filed |
|---|---|---|---|---|
| EcoR1 Capital, LLCincl. EcoR1 Capital Fund Qualified, L.P., Oleg Nodelman | 30.70% | 22.97M | 13D | Nov 19, 2025 ↗ |
| Rubric Capital Management LP | 9.49% | 7.00M | 13G | May 15, 2026 ↗ |
| Perceptive Advisors LLC | 5.40% | 3.97M | 13G | Apr 15, 2026 ↗ |
InsidersForm 4
| Insider | Role | Shares | % outstanding | Filed |
|---|---|---|---|---|
| EcoR1 Capital, LLC | director, 10 percent owner: | 22.97M | 31.22% | Jun 27, 2025 |
| Gregory Austin Ciongoli | director | 493.5K | 0.67% | Aug 12, 2025 |
| Kenneth Galbraith | director, officer: Chair & CEO | 226.8K | 0.31% | Jan 12, 2026 |
| Mark Hollywood | officer: EVP & Chief Operating Officer | 133.9K | 0.18% | Jul 6, 2026 |
| Paul Andrew Moore | officer: Chief Scientific Officer | 48.5K | 0.07% | Jan 12, 2026 |
| Jeffrey T. L. Smith | officer: EVP & Chief Medical Officer | 26.7K | 0.04% | Jan 12, 2026 |
| Leone D. Patterson | officer: EVP, Chief Bus & Fin Officer | 459 | 0.00% | Jan 7, 2026 |
2 ten-percent owners hold 8.97M shares by Form 4 — the 13D/G table above shows those stakes, the figure above counts officers and directors only · 12 people have not refiled in the last 18 months (17.75M shares), so they are not in the figure above
Latest trades
| Date | Insider | Type | Shares | Avg price | Owned after |
|---|---|---|---|---|---|
| Jan 12, 2026 | Mark Hollywoodofficer: EVP & Chief Operating Officer | Sale | 6,120 | $22.67 | 132,913 |
| Jan 12, 2026 | Kenneth Galbraithdirector, officer: Chair & CEO | Sale | 30,424 | $22.67 | 226,842 |
| Jan 12, 2026 | Paul Andrew Mooreofficer: Chief Scientific Officer | Sale | 9,560 | $22.67 | 48,497 |
| Jan 12, 2026 | Jeffrey T. L. Smithofficer: EVP & Chief Medical Officer | Sale | 9,310 | $22.67 | 26,708 |
| Jan 5, 2026 | Paul Andrew Mooreofficer: Chief Scientific Officer | Sale · 2 lots | 20,110 | $25.10 | 31,212 |
| Jan 5, 2026 | Kenneth Galbraithdirector, officer: Chair & CEO | Sale · 2 lots | 54,343 | $25.10 | 158,286 |
| Jan 5, 2026 | Jeffrey T. L. Smithofficer: EVP & Chief Medical Officer | Sale | 10,538 | $25.10 | 18,352 |
| Dec 22, 2025 | Kenneth Galbraithdirector, officer: Chair & CEO | Sale | 47,528 | $27.02 | 133,275 |
CongressHouse and Senate disclosures
Not reported.