Amendment to Schedule 13D Filing for SAB Biotherapeutics, Inc.

This filing is an amendment to a previously submitted Schedule 13D, reporting changes in beneficial ownership of SAB Biotherapeutics, Inc. common stock by RA Capital Management, L.P., Peter Kolchinsky, Rajeev Shah, and RA Capital Healthcare Fund, L.P. (collectively, the "Reporting Persons"). The amendment details a transaction on March 19, 2026, where the Fund purchased pre-funded warrants for 2,753,246 shares of common stock at $3.8499 per share, totaling $10,599,721.78, funded by the Fund's working capital. The Reporting Persons collectively hold 7,311,225 shares, representing 9.9% of the outstanding common stock. Beneficial ownership is primarily attributed to RA Capital Management, L.P. due to its investment management role and delegated voting and disposal powers. The filing also clarifies the terms of the pre-funded warrants, including their exercise price, non-expiring nature, and beneficial ownership blocker provisions that limit ownership to 9.99% of outstanding shares. No other transactions or changes in beneficial ownership have occurred since the last amendment.