In the first quarter, Uber lost about $520 million before interest, taxes, depreciation and amortization, according to people familiar with the matter. In the second quarter, the losses significantly exceeded $750 million, including a roughly $100 million shortfall in the U.S., those people said. Driver subsidies are responsible for the majority of the losses globally, Gupta told investors, according to people familiar with the matter. “You won’t find too many technology companies that could lose this much money, this quickly,” said Aswath Damodaran, a business professor at New York University who has written skeptically of Uber’s astronomical valuation on his blog. Uber’s losses and revenue have generally grown in lockstep as the company’s global ambitions have expanded. Amazon.com is famous for losing money while increasing its market value, but its biggest loss ever totaled $1.4 billion in 2000. “It’s hardly rare for companies to lose large sums of money as they try to build significant markets and battle for market share,” said Joe Grundfest, a professor of law and business at Stanford.