SCHEDULE: Magnetar Funds Disclose 5.87% Stake in Astria Therapeutics

Magnetar Financial and its affiliates have reported a 5.87% beneficial ownership in Astria Therapeutics, Inc., acquired for merger arbitrage purposes following the BioCryst merger announcement.

Summary

• Magnetar Financial LLC, Magnetar Capital Partners LP, Supernova Management LLC, and David J. Snyderman (collectively, the "Reporting Persons") have filed a Schedule 13D.
• The Reporting Persons beneficially own 3,312,202 shares of Astria Therapeutics, Inc. common stock, representing approximately 5.87% of the outstanding shares as of October 22, 2025.
• Shares were acquired on behalf of various funds managed by Magnetar Financial, including PRA Master Fund, Systematic Master Fund, Relative Value Master Fund, and two Managed Accounts.
• The aggregate amount of funds used for purchasing these shares was $39,478,129.72, excluding commissions and other execution-related costs.
• The primary purpose of the acquisition was to receive merger consideration upon the consummation of the previously announced merger between Astria Therapeutics, Inc. and BioCryst Pharmaceuticals, Inc.
• Under the merger agreement, each Astria share will be converted into 0.59 shares of BioCryst common stock and $8.55 in cash.

Sentiment

Score: 7

Explanation: The filing indicates a strategic investment by a sophisticated financial entity (Magnetar) in Astria Therapeutics, specifically to capitalize on a publicly announced merger. This suggests a positive outlook on the merger's completion and the value of the merger consideration. While not directly about Astria's operational performance, it reflects confidence in the announced transaction.

Positives

• The Reporting Persons are positioning themselves to benefit from the announced merger consideration, indicating confidence in the merger's completion.
• The acquisition of shares after the merger announcement suggests a strategic arbitrage play, aiming to capture the spread between Astria's current market price and the implied merger consideration.

Negatives

• No direct negatives for Astria Therapeutics are presented in this filing, as it primarily concerns an investor's position and strategy related to a merger.

Risks

• The primary risk for the Reporting Persons is that the merger between Astria Therapeutics, Inc. and BioCryst Pharmaceuticals, Inc. may not be consummated as planned, or may be delayed, which would impact the expected merger consideration.
• Market fluctuations in the value of BioCryst Common Stock could affect the total value of the merger consideration received by the Reporting Persons.

Future Outlook

The Reporting Persons intend to receive the merger consideration upon the consummation of the merger between Astria Therapeutics, Inc. and BioCryst Pharmaceuticals, Inc. They reserve the right to acquire or dispose of additional securities of Astria Therapeutics, Inc. or change their intentions regarding the transaction.

Management Comments

• The Reporting Persons acquired the 3,312,202 shares on behalf of the Funds after the public announcement of the Agreement and Plan of Merger for purposes of receiving the merger consideration upon consummation of the Merger.

Industry Context

This filing reflects a common strategy in the biotechnology and pharmaceutical sectors where M&A activity is frequent. Investment firms like Magnetar often engage in merger arbitrage, buying shares of target companies after a merger announcement to profit from the spread between the current market price and the announced acquisition price, assuming the deal closes.

Comparison to Industry Standards

• Magnetar's strategy of acquiring a significant stake (5.87%) in a target company post-merger announcement is a standard merger arbitrage practice, common among hedge funds and institutional investors specializing in event-driven strategies.
• The use of margin loans for acquisitions is a typical financing method for such investment strategies, aiming to enhance returns.
• The detailed disclosure of share purchases and sales, including weighted average prices, aligns with regulatory requirements for Schedule 13D filings, providing transparency into the arbitrage activity.

Corporate Governance

Stakeholder Impact

• Shareholders (Astria Therapeutics): The filing highlights a significant institutional investor taking a position to benefit from the merger, potentially reinforcing market confidence in the deal's completion.
• Shareholders (BioCryst Pharmaceuticals): The filing indicates a large investor is acquiring shares of the target company, which could be seen as a positive signal for the acquiring company's strategic move.

Next Steps

• Consummation of the merger between Astria Therapeutics, Inc. and BioCryst Pharmaceuticals, Inc.
• Reporting Persons may acquire additional securities or dispose of current holdings in the open market, in privately negotiated transactions, or otherwise.

Key Dates

Recommendation

This filing primarily details a merger arbitrage position taken by Magnetar. For existing Astria Therapeutics shareholders, the recommendation is to hold until the merger closes to receive the announced consideration, assuming comfort with the terms and the risk of the merger not closing. For new investors, buying Astria shares now would be a merger arbitrage play, which carries specific risks and is typically undertaken by sophisticated investors. The filing itself does not provide new information about Astria's intrinsic value or operational performance, but rather an investor's strategy based on a known event.

Keywords

Astria Therapeutics, BioCryst Pharmaceuticals, Magnetar Financial, Schedule 13D, Merger Arbitrage, Beneficial Ownership, Investment Adviser, Common Stock, SEC Filing, Biotechnology