Tesla Inc fell after the stock was downgraded by UBS Group AG, which cited concerns that the electric carmaker’s shares have risen “too much, too soon” on optimism over its artificial intelligence (AI) plans.

Tesla was 1.6% lower in US premarket trading as of 4.30am in New York. The stock sank 8.4% Thursday, snapping an 11-day winning streak, as Tesla was said to postpone its planned robotaxi unveiling to October from next month to allow teams working on the project more time to build additional prototypes.

The electric-vehicle maker is among the 10 most expensive stocks in the S&P 500 Index, far surpassing the rest of the megacap technology cohort. Before Thursday’s slump, its shares had soared 44% through Wednesday in their latest rally on bets that billionaire founder Elon Musk can transform the company into an AI powerhouse.

“If market enthusiasm for AI diminishes, this may impact Tesla’s multiple,” UBS analysts including Joseph Spak wrote in a note, cutting their rating to sell from neutral.

The downgrade is warranted “given the lack of visibility and the risk that growth opportunities materialise on a longer time horizon (or not at all),” the analysts wrote, noting the stock trades at more than 80 times one-year forward estimated earnings.

UBS’s move mirrors mounting concerns over valuations of companies tied to AI technology, evidenced by a selloff overnight of Big Tech shares. Tesla is also facing a subdued outlook for electric cars, weighing on its sales and earnings.

The premium that investors ascribe to Tesla for its gamut of initiatives has grown recently on AI enthusiasm and “one would need to see an even larger opportunity to justify a buy rating,” the UBS analysts wrote.  

UBS analysts raised their 12-month target on the stock from to US$197 from US$147, implying an 18% decline from Thursday’s close. They employed a higher price-to-earnings multiple than before to arrive at the new target.

  - Bloomberg