Uber casts $50 billion shadow over public markets By: CNBC.com News May 12, 2015 at 11:14 AM EDT Uber is the latest start-up to reportedly reach a $50 billion valuation without going public. Is it doing the public a disservice? Read More >> Related Stocks: Alibaba Group Holding Ltd BlackRock Facebook General Motors Google, Inc. Kellogg Co T.Rowe Price Group