SCHEDULE: ADAR1 Capital Management Discloses 9.9% Stake in Equillium

ADAR1 Capital Management, its general partner, and Daniel Schneeberger have jointly reported a 9.9% beneficial ownership stake in Equillium, Inc. as of September 30, 2025.

Summary

• ADAR1 Capital Management, LLC, ADAR1 Capital Management GP, LLC, and Daniel Schneeberger (the "Reporting Persons") have filed a Schedule 13G disclosing their beneficial ownership in Equillium, Inc.
• As of September 30, 2025, ADAR1 Capital Management, LLC beneficially owns 6,117,290 shares of Equillium's common stock, representing 9.9% of the class. This includes 4,327,145 shares held by ADAR1 Partners, LP, 699,101 shares by Spearhead Insurance Solutions IDF, LLC, 533,742 shares by ADAR1 SPV I, LP, and 557,302 shares underlying prefunded warrants.
• ADAR1 Capital Management GP, LLC beneficially owns 6,194,882 shares, also representing 9.9% of the class. This includes 4,327,145 shares held by ADAR1 Partners, LP, 533,742 shares by ADAR1 SPV I, LP, and 1,333,995 shares underlying prefunded warrants.
• Daniel Schneeberger beneficially owns 6,117,290 shares, representing 9.9% of the class, through his roles as manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC.
• The reported beneficial ownership excludes 2,877,208 shares (for ADAR1 Capital Management, LLC and Daniel Schneeberger) and 1,652,311 shares (for ADAR1 Capital Management GP, LLC) underlying prefunded warrants, due to 9.99% beneficial ownership limitations.
• The percentage ownership is calculated based on 60,676,837 shares of Equillium Inc. common stock outstanding as of September 30, 2025, as reported in Equillium's 10Q filed on November 13, 2025.

Sentiment

Score: 5

Explanation: The filing is a standard Schedule 13G disclosure of beneficial ownership, providing factual information without expressing positive or negative sentiment regarding the issuer's performance or prospects.

Risks

• The exchange and exercise of certain prefunded warrants are subject to 9.99% beneficial ownership limitations, which could restrict the immediate full conversion of these warrants by the Reporting Persons.

Future Outlook

NA

Industry Context

NA

Stakeholder Impact

• Shareholders: Provides transparency regarding a significant institutional investor's stake in the company.
• Management: Indicates a substantial passive investment by ADAR1 Capital Management and its affiliates.

Key Dates

Keywords

Equillium, ADAR1 Capital Management, Schedule 13G, beneficial ownership, common stock, prefunded warrants, institutional ownership, investment management, passive investment