Adage Capital Management Reports New 9.71% Stake in Nine Energy Service, Inc.

On July 9, 2026, Adage Capital Management, L.P. (ACM) filed a Schedule 13G reporting a significant new ownership stake in Nine Energy Service, Inc. (NINE). As of the event date on March 31, 2026, the reporting persons—including ACM, Robert Atchinson, and Phillip Gross—collectively beneficially own 1,355,149 shares of common stock. This position represents approximately 9.71% of the company's outstanding shares, based on 13,950,000 shares reported as of March 5, 2026. ACM serves as the investment manager for Adage Capital Partners, L.P. (ACP), which directly holds the shares. Robert Atchinson and Phillip Gross maintain shared voting and dispositive power over these securities through their roles as managing members of the entities acting as general partners to ACM and ACP. The filing indicates a substantial increase from a zero-share position previously, marking a major entry into the issuer's equity by the Boston-based investment adviser. The filing was made pursuant to Rule 13d-1(d).