Rubric Capital Management and David Rosen report a significant stake in Zymeworks Inc. They beneficially own 5,750,000 shares of Zymeworks common stock, representing 7.68% of the outstanding shares. This ownership is reported as being held in the ordinary course of business and not for the purpose of changing or influencing control of the company.
The percentage is based on 74,836,534 Zymeworks common shares outstanding as of November 4, 2025, as disclosed in the company’s Form 10-Q. Rubric Capital has shared voting and dispositive power over these shares, primarily through Rubric Capital Master Fund LP.
Positive
None.
Negative
None.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
Zymeworks Inc.
(Name of Issuer)
Common Stock, $0.00001 par value per share
(Title of Class of Securities)
98985Y108
(CUSIP Number)
12/31/2025
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
SCHEDULE 13G
CUSIP No.
98985Y108
1
Names of Reporting Persons
Rubric Capital Management LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,750,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,750,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,750,000.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
7.68 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP No.
98985Y108
1
Names of Reporting Persons
David Rosen
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,750,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,750,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,750,000.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
7.68 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Zymeworks Inc.
(b)
Address of issuer's principal executive offices:
108 Patriot Drive, Suite A, Middletown, DE 19709
Item 2.
(a)
Name of person filing:
This statement is filed by:
(i) Rubric Capital Management LP ("Rubric Capital"), the investment adviser to certain investment funds and/or accounts (collectively, the "Rubric Funds") that hold the shares of Common Stock, $0.00001 par value (the "Common Stock") of Zymeworks Inc., a Delaware corporation (the "Issuer") reported herein; and
(ii) David Rosen ("Mr. Rosen"), Managing Member of Rubric Capital Management GP LLC, the general partner of Rubric Capital.
The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons."
The filing of this statement should not be construed as an admission that any of the forgoing persons or any Reporting Person is, for the purposes of Section 13 of the Act, the beneficial owner of the Shares reported herein.
(b)
Address or principal business office or, if none, residence:
The address of the principal business office of each of the Reporting Persons is 155 East 44th St, Suite 1630, New York, NY 10017.
(c)
Citizenship:
Rubric Capital is a Delaware limited partnership. Mr. Rosen is a citizen of the United States of America.
(d)
Title of class of securities:
Common Stock, $0.00001 par value per share
(e)
CUSIP No.:
98985Y108
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
The information required by Items 4(a) - (c) is set forth in Rows 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
The percentage set forth in Row (11) of the cover page for each of the Reporting Persons and in Item 4(b) is based on the 74,836,534 shares of Common Stock outstanding as of November 4, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2025, filed with the Securities and Exchange Commission on November 6, 2025.
(b)
Percent of class:
7.68 %
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(ii) Shared power to vote or to direct the vote:
The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(iii) Sole power to dispose or to direct the disposition of:
The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(iv) Shared power to dispose or to direct the disposition of:
The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
See Item 2(a). Rubric Capital Master Fund LP, a Rubric Fund, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, more than 5% of the Common Stock.
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
What ownership stake in Zymeworks Inc. does Rubric Capital report in this Schedule 13G/A?
Rubric Capital Management and David Rosen report beneficial ownership of 5,750,000 Zymeworks Inc. common shares, representing 7.68% of the outstanding class. This makes them a significant shareholder based on the company’s reported 74,836,534 shares outstanding as of November 4, 2025.
Who are the reporting persons in the Zymeworks (ZYME) Schedule 13G/A filing?
The reporting persons are Rubric Capital Management LP and David Rosen. Rubric Capital is the investment adviser to certain funds holding Zymeworks shares, and Rosen is the Managing Member of Rubric Capital Management GP LLC, the general partner of Rubric Capital.
How much voting and dispositive power over Zymeworks (ZYME) shares does Rubric Capital have?
Rubric Capital and David Rosen report shared voting power over 5,750,000 shares and shared dispositive power over 5,750,000 shares, with no sole voting or dispositive power. This means decisions over these shares are made jointly, not individually.
What percentage of Zymeworks (ZYME) does the 5,750,000 shares represent?
The filing states that 5,750,000 Zymeworks common shares represent 7.68% of the class. This percentage is calculated using 74,836,534 shares outstanding as of November 4, 2025, as disclosed in Zymeworks’ Form 10-Q for the quarter ended September 30, 2025.
Is Rubric Capital’s stake in Zymeworks (ZYME) intended to influence control of the company?
The certification states the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Zymeworks. They are also not held in connection with any control-related transaction, except as allowed for certain nomination activities.
Which Rubric fund has rights to dividends or sale proceeds from Zymeworks (ZYME) shares?
The filing notes that Rubric Capital Master Fund LP, one of the Rubric Funds, has the right to receive or direct the receipt of dividends or sale proceeds from more than 5% of Zymeworks’ common stock, reflecting its economic interest in the reported position.
What type of reporting persons are identified in the Zymeworks (ZYME) Schedule 13G/A?
Rubric Capital Management LP is identified as an investment adviser (IA), and David Rosen is classified as a holding company/control person (HC). These classifications are standard Schedule 13G categories describing their regulatory and control roles over the reported holdings.