Zymeworks Inc.
ZYME- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001937653
No open-market purchases or sales by Zymeworks Inc. insiders were filed in the last 90 days; 202 institutions reported holding it in 13F filings for Q2 2026, worth $1.79B in total; no superinvestor holds it.
Holders of 5% or more of ZYME
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Zymeworks Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| EcoR1 Capital, LLC | 13D/A | 30.70%23.0M shares | 0.00 ppfrom 30.70% | Dec 23, 20247 filings | Nov 19, 2025 | SEC |
| Morgan Stanley | 13G/A | 5.80%4.06M shares | – | May 7, 20251 filing | May 7, 2025 | SEC |
| Biotechnology Value Fund L P | 13G/A | 5.20%3.94M shares | – | Nov 14, 20251 filing | Nov 14, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
13 Schedule 13D and 13G filings on Zymeworks Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Nov 19, 20255:39 PM ET | EcoR1 Capital, LLCand 2 others | 13D/A | 30.70%23.0M shares | 0.00 ppfrom 30.70% | Nov 16, 2025 | SEC |
| Nov 14, 20254:26 PM ET | Biotechnology Value Fund L Pand 9 others | 13G/A | 5.20%3.94M shares | – | Sep 30, 2025 | SEC |
| Nov 14, 20254:15 PM ET | Redmile Group, LLCand 1 other | 13G/A | 4.90%3.71M shares | −0.70 ppfrom 5.60%Below 5% | Sep 30, 2025 | SEC |
| Aug 14, 20254:20 PM ET | Redmile Group, LLCand 2 others | 13G/A | 5.60%4.15M shares | −1.40 ppfrom 7.00% | Jun 30, 2025 | SEC |
| Jul 16, 20257:02 PM ET | BlackRock, Inc. | 13G/A | 4.80%3.56M shares | –Below 5% | Jun 30, 2025 | SEC |
| Jun 27, 20256:14 PM ET | EcoR1 Capital, LLCand 2 others | 13D | 30.70%23.0M shares | +5.30 ppfrom 25.40% | Jun 26, 2025 | SEC |
| May 7, 202511:43 AM ET | Morgan Stanleyand 1 other | 13G/A | 5.80%4.06M shares | – | Mar 31, 2025 | SEC |
| Apr 8, 20254:24 PM ET | EcoR1 Capital, LLCand 2 others | 13D/A | 25.40%17.7M shares | +1.20 ppfrom 24.20% | Apr 4, 2025 | SEC |
| Mar 17, 20257:50 PM ET | EcoR1 Capital, LLCand 2 others | 13D/A | 24.20%16.9M shares | +1.40 ppfrom 22.80% | Mar 13, 2025 | SEC |
| Feb 18, 20256:25 PM ET | EcoR1 Capital, LLCand 2 others | 13D/A | 22.80%15.7M shares | +0.40 ppfrom 22.40% | Feb 17, 2025 | SEC |
| Feb 14, 20258:04 PM ET | Redmile Group, LLCand 2 others | 13G/A | 7.00%4.84M shares | – | Dec 31, 2024 | SEC |
| Jan 13, 20257:18 PM ET | EcoR1 Capital, LLCand 2 others | 13D/A | 22.40%15.4M shares | +1.10 ppfrom 21.30% | Jan 10, 2025 | SEC |
| Dec 23, 20247:54 PM ET | EcoR1 Capital, LLCand 2 others | 13D/A | 21.30%14.7M shares | – | Dec 19, 2024 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Zymeworks Inc. shares.
No Form 144 notices for Zymeworks Inc. are on file.