Comparable stake leader
EcoR1 Capital, LLC
SEC ownership of Zymeworks Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001937653.
Disclosed value leader
EcoR1 Capital, LLC
Comparable rows
50/50
Latest evidence
08 Apr 2026
- Public ticker
- ZYME on Nasdaq
- Parsed ownership sources
- 13F, 13D/G, and 3/4/5
- Largest SEC-reported holder
- EcoR1 Capital, LLC
- Latest 13D/G holder
- EcoR1 Capital, LLC
- Latest parsed ownership date
- 08 Apr 2026
- Issuer CIK
- 0001937653
- Issuer location
- Middletown, DE
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Zymeworks Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
EcoR1 Capital, LLC
Disclosed value leader
EcoR1 Capital, LLC
Comparable rows
50/50
Latest evidence
08 Apr 2026
13F
13D/G
3/4/5
Lead comparable stake: 31%
13D/G row: EcoR1 Capital, LLC
Showing 1-8 of 50 holder rows.
Quick read
EcoR1 Capital, LLC leads the comparable SEC ownership view at 31%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens EcoR1 Capital, LLC's linked filing trail.
Comparable ownership
Top 5
EcoR1 Capital, LLC
31%
Rubric Capital Management LP
9.5%
PERCEPTIVE ADVISORS LLC
5.4%
BIOTECHNOLOGY VALUE FUND L P
5.2%
Redmile Group, LLC
4.9%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| EcoR1 Capital, LLC |
13F
13D/G
3/4/5
Company · Director, 10%+ Owner
|
31%
from 13D/G
|
$575,178,516
22,970,388 shares
|
— | 31 Mar 2026 |
| Rubric Capital Management LP |
13D/G
13F
Company
|
9.5%
|
$175,280,000
7,000,000 shares
|
+$31,300,000 | 31 Mar 2026 |
| PERCEPTIVE ADVISORS LLC |
13D/G
13F
Company
|
5.4%
|
$99,527,035
3,974,579 shares
|
$0 | 08 Apr 2026 |
| BIOTECHNOLOGY VALUE FUND L P |
13D/G
BVF PARTNERS L P/IL
|
5.2%
|
$67,271,988
3,938,641 shares
|
$0 | 30 Sep 2025 |
| Redmile Group, LLC |
13D/G
3/4/5
13F
10%+ Owner · Company
|
4.9%
|
$63,294,210
3,705,750 shares
|
-$7,598,499 | 30 Sep 2025 |
| BlackRock, Inc. |
13F
13D/G
Company
|
4.8%
from 13D/G
|
$114,029,354
4,553,888 shares
|
— | 31 Mar 2026 |
| MORGAN STANLEY |
13D/G
13F
Company
|
3.4%
|
$67,062,249
2,519,243 shares
|
-$40,886,430 | 31 Dec 2025 |
| BVF INC/IL |
13F
Company
|
5.1%
|
$93,502,916
3,734,142 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$4,673,751.
Buys
$0
Insiders: 0
Sells
$4,673,751
Insiders: 4
Net
-$4,673,751
Shares: -187,933
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 187,933
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 187,933 | $0 | $4,673,751 | -$4,673,751 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 31 reporting-owner rows connected to Zymeworks Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
31
Largest Forms 3/4/5 holder
EcoR1 Capital, LLC
Net 12M change
-$4,673,751
Latest report
13 May 2026
Recent insider transactions for Zymeworks Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Paul R. Schneider | ZYME | Restricted Stock Unit | Award | 119,000 | 119,000 | 13 May 2026 | Direct | |||
| Paul R. Schneider | ZYME | Stock Option (Right to Buy) | Award | 178,000 | 178,000 | 13 May 2026 | Direct | |||
| Adam Schayowitz | ZYME | Performance Stock Unit | Award | 76,000 | 76,000 | 09 Apr 2026 | Direct | |||
| Adam Schayowitz | ZYME | Restricted Stock Unit | Award | 47,000 | 47,000 | 09 Apr 2026 | Direct | |||
| Adam Schayowitz | ZYME | Stock Option (Right to Buy) | Award | 70,000 | 70,000 | 09 Apr 2026 | Direct | |||
| Scott Platshon | ZYME | Performance Stock Unit | Award | 76,000 | 76,000 | 09 Apr 2026 | Direct | |||
| Scott Platshon | ZYME | Restricted Stock Unit | Award | 47,000 | 47,000 | 09 Apr 2026 | Direct | |||
| Scott Platshon | ZYME | Stock Option (Right to Buy) | Award | 70,000 | 70,000 | 09 Apr 2026 | Direct | |||
| Kristin Stafford | ZYME | Restricted Stock Unit | Award | 169,000 | 119,000 | 06 Apr 2026 | Direct | |||
| Kristin Stafford | ZYME | Stock Option (Right to Buy) | Award | 178,000 | 178,000 | 06 Apr 2026 | Direct | |||
| Mark Hollywood | ZYME | Common Stock | Sale | -4.4% | $138,762 | $22.67 | -6,120 | 132,913 | 12 Jan 2026 | Direct |
| Mark Hollywood | ZYME | Common Stock | Options Exercise | 14.6% | 17,666 | 139,033 | 12 Jan 2026 | Direct | ||
| Mark Hollywood | ZYME | Performance Stock Unit | Award | 66,000 | 66,000 | 12 Jan 2026 | Direct | |||
| Mark Hollywood | ZYME | Restricted Stock Unit | Award | 47,000 | 47,000 | 12 Jan 2026 | Direct | |||
| Mark Hollywood | ZYME | Stock Option (Right to Buy) | Award | 70,000 | 70,000 | 12 Jan 2026 | Direct | |||
| Mark Hollywood | ZYME | Restricted Stock Unit | Options Exercise | -33.3% | -17,666 | 35,334 | 12 Jan 2026 | Direct | ||
| Brian N. Cherry | ZYME | Restricted Stock Unit | Award | 15,400 | 15,400 | 12 Jan 2026 | Direct | |||
| Brian N. Cherry | ZYME | Stock Option (Right to Buy) | Award | 23,000 | 23,000 | 12 Jan 2026 | Direct | |||
| Smith Jeffrey T. L. | ZYME | Common Stock | Sale | -25.8% | $211,090 | $22.67 | -9,310 | 26,708 | 12 Jan 2026 | Direct |
| Smith Jeffrey T. L. | ZYME | Common Stock | Options Exercise | 96.3% | 17,666 | 36,018 | 12 Jan 2026 | Direct | ||
| Smith Jeffrey T. L. | ZYME | Restricted Stock Unit | Options Exercise | -33.3% | -17,666 | 35,334 | 12 Jan 2026 | Direct | ||
| Gregory Austin Ciongoli | ZYME | Restricted Stock Unit | Award | 7,700 | 7,700 | 12 Jan 2026 | Direct | |||
| Gregory Austin Ciongoli | ZYME | Stock Option (Right to Buy) | Award | 11,500 | 11,500 | 12 Jan 2026 | Direct | |||
| Kelvin Neu | ZYME | Restricted Stock Unit | Award | 7,700 | 7,700 | 12 Jan 2026 | Direct | |||
| Kelvin Neu | ZYME | Stock Option (Right to Buy) | Award | 11,500 | 11,500 | 12 Jan 2026 | Direct | |||
| Robert E. Landry | ZYME | Restricted Stock Unit | Award | 7,700 | 7,700 | 12 Jan 2026 | Direct | |||
| Robert E. Landry | ZYME | Stock Option (Right to Buy) | Award | 11,500 | 11,500 | 12 Jan 2026 | Direct | |||
| Alessandra Cesano | ZYME | Restricted Stock Unit | Award | 7,700 | 7,700 | 12 Jan 2026 | Direct | |||
| Alessandra Cesano | ZYME | Stock Option (Right to Buy) | Award | 11,500 | 11,500 | 12 Jan 2026 | Direct | |||
| Carlos Campoy | ZYME | Restricted Stock Unit | Award | 7,700 | 7,700 | 12 Jan 2026 | Direct | |||
| Carlos Campoy | ZYME | Stock Option (Right to Buy) | Award | 11,500 | 11,500 | 12 Jan 2026 | Direct | |||
| Susan Mahony | ZYME | Restricted Stock Unit | Award | 7,700 | 7,700 | 12 Jan 2026 | Direct | |||
| Susan Mahony | ZYME | Stock Option (Right to Buy) | Award | 11,500 | 11,500 | 12 Jan 2026 | Direct | |||
| Paul Andrew Moore | ZYME | Common Stock | Sale | -16.5% | $216,759 | $22.67 | -9,560 | 48,497 | 12 Jan 2026 | Direct |
| Paul Andrew Moore | ZYME | Common Stock | Options Exercise | 43.7% | 17,666 | 58,057 | 12 Jan 2026 | Direct | ||
| Paul Andrew Moore | ZYME | Performance Stock Unit | Award | 66,000 | 66,000 | 12 Jan 2026 | Direct | |||
| Paul Andrew Moore | ZYME | Restricted Stock Unit | Award | 47,000 | 47,000 | 12 Jan 2026 | Direct | |||
| Paul Andrew Moore | ZYME | Stock Option (Right to Buy) | Award | 70,000 | 70,000 | 12 Jan 2026 | Direct | |||
| Paul Andrew Moore | ZYME | Restricted Stock Unit | Options Exercise | -33.3% | -17,666 | 35,334 | 12 Jan 2026 | Direct | ||
| Kenneth Galbraith | ZYME | Common Stock | Sale | -11.8% | $689,819 | $22.67 | -30,424 | 226,842 | 12 Jan 2026 | Direct |
| Kenneth Galbraith | ZYME | Common Stock | Options Exercise | 33.1% | 64,000 | 257,266 | 12 Jan 2026 | Direct | ||
| Kenneth Galbraith | ZYME | Performance Stock Unit | Award | 222,000 | 222,000 | 12 Jan 2026 | Direct | |||
| Kenneth Galbraith | ZYME | Restricted Stock Unit | Award | 144,000 | 144,000 | 12 Jan 2026 | Direct | |||
| Kenneth Galbraith | ZYME | Stock Option (Right to Buy) | Award | 216,000 | 216,000 | 12 Jan 2026 | Direct | |||
| Kenneth Galbraith | ZYME | Restricted Stock Unit | Options Exercise | -33.3% | -64,000 | 128,000 | 12 Jan 2026 | Direct | ||
| Leone D. Patterson | ZYME | Common Stock | Award | 459 | 459 | 06 Jan 2026 | Direct | |||
| Smith Jeffrey T. L. | ZYME | Common Stock | Sale | -36.5% | $264,471 | $25.10 | -10,538 | 18,352 | 05 Jan 2026 | Direct |
| Smith Jeffrey T. L. | ZYME | Common Stock | Options Exercise | 225% | 20,000 | 28,890 | 05 Jan 2026 | Direct | ||
| Smith Jeffrey T. L. | ZYME | Restricted Stock Unit | Options Exercise | -50% | -20,000 | 20,000 | 05 Jan 2026 | Direct | ||
| Kenneth Galbraith | ZYME | Common Stock | Sale | -25.6% | $1,363,841 | $25.10 | -54,343 | 158,286 | 05 Jan 2026 | Direct |
* marks a reported price that did not pass the local price check.