SCHEDULE: Rubric Capital Management and David Rosen Disclose 5.38% Stake in TransAlta Corporation

Rubric Capital Management LP and David Rosen have jointly disclosed a beneficial ownership of 5.38% of TransAlta Corporation's common shares, totaling 15,948,151 shares, as of June 30, 2025.

Summary

• Rubric Capital Management LP and David Rosen, collectively referred to as the Reporting Persons, have filed a Schedule 13G disclosing their beneficial ownership in TransAlta Corporation.
• As of June 30, 2025, the Reporting Persons beneficially own an aggregate of 15,948,151 common shares of TransAlta Corporation.
• This ownership represents 5.38% of TransAlta Corporation's common shares outstanding.
• The percentage is calculated based on 296,449,829 common shares outstanding as of May 20, 2025, as reported by TransAlta Corporation in its Form 6-K filed on May 28, 2025.
• Rubric Capital Management LP is a Delaware limited partnership acting as an investment adviser, and David Rosen is its Managing Member.
• The shares are held with shared voting power and shared dispositive power by both reporting persons.
• The acquisition and holding of these securities are stated to be in the ordinary course of business and not for the purpose of changing or influencing control of TransAlta Corporation, other than activities solely in connection with a nomination under Rule 240.14a-11.

Sentiment

Score: 5

Explanation: The document is a factual disclosure of beneficial ownership, which is neutral in sentiment. It does not contain positive or negative financial performance indicators or strategic announcements.

Future Outlook

NA

Management Comments

• The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint acquisition statements.
• The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate.
• 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 Rule 240.14a-11.

Industry Context

NA

Stakeholder Impact

• Shareholders: Disclosure of a significant institutional stake (5.38%) provides transparency regarding the ownership structure and may influence investor perception, especially given the statement about not seeking control but allowing for nominations.

Next Steps

• Subsequent amendments to this Schedule 13G statement will be filed on behalf of each of the undersigned.
• Each undersigned will be responsible for the timely filing of such amendments and for the completeness and accuracy of their own information.

Key Dates

Keywords

TransAlta Corporation, Rubric Capital Management LP, David Rosen, Schedule 13G, Beneficial Ownership, Common Shares, Investment Adviser, Institutional Ownership, SEC Filing, Shareholder Disclosure