This AI infrastructure stock is trading at an expensive valuation, but it can justify that thanks to a huge revenue backlog.Neocloud provider Nebius Group (NBIS 6.46%) delivered sizzling returns on the market in the past year, rising 475% as of this writing. This stunning surge in the stock is backed by the outstanding growth in the company's revenue in recent quarters, a result of the remarkable demand for its artificial intelligence (AI) data centers.This phenomenal rally may lead investors to think that ...