Nvidia (NVDA) has become the market darling once again. Diane King Hall notes Citi's new price target raise on the A.I. giant over data center and chip expansion prospects. However, Redburn downgraded another A.I. stock: Applied Materials (AMAT). Diane talks about why China is impacting the analyst's view. CrowdStrike (CRWD) also got a downgrade from Piper Sandler as the stock trades near all-time highs.