SCHEDULE: Rubric Capital Discloses 7.68% Stake in Zymeworks Inc.

Rubric Capital Management LP and David Rosen have disclosed a 7.68% beneficial ownership stake in Zymeworks Inc., totaling 5,750,000 common shares.

Summary

• Rubric Capital Management LP and David Rosen, Managing Member of Rubric Capital Management GP LLC, have filed an Amendment No. 1 to Schedule 13G.
• The filing reports beneficial ownership of 5,750,000 shares of Zymeworks Inc. Common Stock.
• This represents 7.68% of Zymeworks Inc.'s outstanding Common Stock.
• The percentage is based on 74,836,534 shares outstanding as of November 4, 2025, as reported in Zymeworks' Form 10-Q.
• Both Rubric Capital and David Rosen share voting and dispositive power over all 5,750,000 shares.
• Rubric Capital Master Fund LP, a Rubric Fund, has the right to receive or direct proceeds from more than 5% of the Common Stock.
• The securities were acquired and are held in the ordinary course of business, not for the purpose of changing or influencing control, except for activities solely in connection with a nomination under Rule 14a-11.

Sentiment

Score: 7

Explanation: StockSavvy.ai views this as a moderately positive development, as a significant institutional stake often implies a vote of confidence in the company's value proposition, even if passive.

Positives

• A significant ownership stake by an institutional investor like Rubric Capital Management LP can signal confidence in Zymeworks Inc.'s long-term prospects.
• The disclosure indicates a substantial commitment from a professional investment adviser.

Negatives

• This filing is a factual disclosure of ownership and does not inherently contain negative financial or operational information about Zymeworks Inc.

Risks

• The filing itself does not detail specific risks related to Zymeworks Inc.'s operations or financial health. It is a disclosure of beneficial ownership.

Future Outlook

This Schedule 13G filing does not contain any forward-looking statements or guidance from Zymeworks Inc. or the reporting persons regarding the issuer's future performance or strategic direction.

Management Comments

• Rubric Capital Management LP and David Rosen certified that the securities were acquired and are held in the ordinary course of business and not for the purpose of or with the effect of changing or influencing the control of Zymeworks Inc., other than activities solely in connection with a nomination under Rule 14a-11.

Industry Context

StockSavvy.ai notes that a significant passive stake by an investment adviser like Rubric Capital Management LP in a biotechnology company such as Zymeworks Inc. is a common occurrence. It suggests that the investor sees value in the company's current strategy or future potential, often without seeking active control. This type of institutional investment can provide a degree of stability and validation for the company within the competitive biotech landscape.

Comparison to Industry Standards

• This filing is a standard disclosure of beneficial ownership, not a performance report, so direct comparisons to industry-specific financial benchmarks or project results are not applicable.
• The 7.68% stake is a notable position for an institutional investor, indicating a significant conviction in Zymeworks Inc. relative to other biotech firms where similar funds might hold smaller, more diversified positions.

Stakeholder Impact

• Shareholders: The disclosure of a significant institutional investor holding a substantial stake may be viewed positively, potentially increasing investor confidence and liquidity.
• Management: Awareness of a large institutional holder may influence strategic decisions, though the filing states no intent to influence control.

Next Steps

• Zymeworks Inc. will continue its operations and report financial results as per SEC requirements.
• Rubric Capital Management LP may adjust its holdings in Zymeworks Inc. in the future, which would necessitate further Schedule 13G or 13D filings if ownership thresholds are crossed.

Key Dates

Recommendation

The filing indicates a significant institutional investment, which can be a positive signal. However, as a Schedule 13G, it provides no new operational or financial performance data for Zymeworks Inc. to warrant a 'buy' or 'sell' recommendation. The information primarily confirms a substantial passive stake, suggesting a 'hold' position for existing investors and further due diligence for potential new investors based on Zymeworks' underlying fundamentals.

Keywords

Zymeworks Inc., Rubric Capital Management, David Rosen, Beneficial Ownership, Schedule 13G, Common Stock, Biotechnology, Investment Adviser, Institutional Ownership