As Tesla shares surged past $300 this week and the company’s market value surpassed Ford’s, even its founder, Elon Musk, acknowledged on Twitter that the company was “absurdly overvalued if based on the past.”

By “the past,” he presumably means old-fashioned valuation measures like price-to-earnings or price-to-sales ratios, the traditional benchmarks for evaluating stock prices. By those measures, Tesla — a company that lost $773 million last year — is indeed off the charts.

Tesla’s market value of nearly $49 billion is not only higher than that of Ford, which earned nearly $11 billion in profit last year, but is within easy striking distance of General Motors, which earned $9.4 billion.

In contrast to Tesla, Ford and G.M. shares have dropped recently on fears that auto sales have hit a cyclical peak. Ford and G.M. executives wouldn’t comment on Tesla’s stock surge, but it’s easy to imagine they’d be tearing their hair out in frustration.