DETROIT — The record pace of auto sales in the United States is slowing down, leaving investors increasingly bearish on auto stocks.

But there is one exception. Tesla, the electric-vehicle upstart, continues to surge.

On Monday, Tesla surpassed Ford Motor in market value for the first time and moved within striking distance of General Motors, starkly illustrating the growing gap in investors’ optimism over its future versus the prospects for the traditional carmakers from Detroit.

While G.M. and Ford may have strong profits and healthy balance sheets, Tesla offers something Wall Street loves much more: the potential for dramatic growth.

“Investors want something that is going to go up in orders of magnitude in six months to six years, and Tesla is that story,” said Karl Brauer, a senior editor at Kelley Blue Book. “Nobody thinks Ford or G.M. is going to do that.”