William Blair bullish on CoreWeave and Nebius as AI buildout accelerates

William Blair initiated coverage of neocloud firms CoreWeave (NASDAQ: CRWV) and Nebius Group (NASDAQ: NBIS) on Wednesday, assigning both firms Outperform ratings. Analyst Jason Ader highlighted CoreWeave's strategic position as a supplier to major hyperscalers and AI labs, citing a $130 billion committed backlog and second-quarter revenue of $2.58 billion that likely surpassed other neoclouds.

Ader emphasized CoreWeave's AI-native architecture and proprietary software, despite competition using similar Nvidia chips. He noted that while capital spending of $37 billion this year and deeply negative free cash flow are concerns, recent contract economics showing higher pricing and contribution margins suggest improving returns on increased investment.

CoreWeave's stock trades at 3.1 times 2027 enterprise value to sales, compared to a peer median of 6.1 times.

Regarding Nebius, Ader observed the company's shift from renting raw computing capacity to a full-stack AI cloud platform. Its annualized revenue run rate grew from around $1.25 billion in 2025 to approximately $3 billion in Q2. Nebius has secured long-term commitments from Microsoft and Meta, raising its contracted power target to about 5 gigawatts.

Ader pointed out the company's stronger balance sheet and lower debt than its peers, providing flexibility to fund expansion. He highlighted an attractive risk/reward for both CoreWeave and Nebius.