Jade Biosciences, Inc.

## Signal Note: Baker Bros. Initiates Position in Jade Biosciences (JBIO) **Note: The reported position value of ~$25.3B appears to be a data error** — likely reflecting an incorrect price or share count in the filing, as this would exceed Baker Bros.' entire AUM and JBIO's market cap. The actual position is likely in the low hundreds of millions range, consistent with the ~1.64M share count. That said, the initiation itself is significant. Baker Bros. taking a new concentrated position in Jade Biosciences — a recently launched autoimmune/inflammation-focused company built around targeted protein degradation (molecular glue and heterobifunctional degraders) — signals high conviction in the platform's therapeutic potential across indications like lupus and other autoimmune diseases. Jade, which emerged in early 2025 with substantial venture backing, is pre