Nebius Group 
NBIS said it agreed to buy Eigen AI for about $643 million in cash and stock, a deal that sent Nebius shares up about 8% on Friday.
The acquisition is set to deepen Nebius’ artificial intelligence push by folding Eigen AI’s inference and post-training optimization tools into Nebius Token Factory, its platform for managing production AI workloads. The company also said the transaction may expand its U.S. footprint, with Eigen AI’s founding team expected to help build an engineering and research presence in the San Francisco Bay Area.
Nebius said the purchase price will be paid through a mix of cash and its own shares. The deal is expected to close in the coming weeks, subject to standard conditions, including antitrust clearance.
The company said the move fits a market where AI developers are looking for more optimized inference systems and larger-scale infrastructure.