William Blair Starts CoreWeave at Outperform as Shares Rise

CoreWeave shares rose in the September 30, 2026 session as William Blair began coverage of the AI-cloud computing company with an outperform rating. The timing put a fresh analyst endorsement behind a stock that was already moving higher on the day. CoreWeave rents out data-center computing power built around Nvidia chips, a business that has drawn heavy investor interest as demand for AI infrastructure grows. A new outperform call from a sell-side firm adds to the case bulls have been making, though the wire item does not detail Blair's price target or the specific reasoning behind the rating. What remains unclear is whether the rating alone explains the day's gain or whether it reinforced a move already underway for other reasons.