Boost Run Inc. (BRUN) is trading at $25.62 (6.7% up) after Citadel Advisors disclosed a passive stake in the company via a Schedule 13G filing dated May 21, 2026.
- The filing reveals that Citadel entities, including Kenneth Griffin, have taken a significant position in the AI cloud infrastructure provider.
- This disclosure has attracted considerable investor interest, positioning the Citadel stake as the primary driver for the stock's significant outperformance against the broader market today.