In a down year for stocks, the 65 percent drop in Tesla’s share price stands out for the scale of wealth vaporized and the unorthodox behavior of its chief executive, Elon Musk.

The collapse of Tesla’s stock price destroyed about $672 billion in market value. And Mr. Musk, once hailed as a genius who remade the car industry, appears increasingly distracted by his acquisition of Twitter and is using the social network to vent his frustrations. He insulted one of his critics this week by describing him as having “tiny testicles.”

The spectacle has stunned investors and analysts. And many are asking what will happen to the stock, the company and Mr. Musk in 2023. The answer largely depends on Mr. Musk and Tesla’s board of directors.

Will he return his attention to Tesla and its myriad challenges? Or will he remain camped out at Twitter? Will Mr. Musk sell more Tesla shares to keep Twitter going after spending $44 billion to buy that company, despite promising not to? Will the Cybertruck, Tesla’s first new passenger vehicle in three years, finally be available for sale? And, perhaps most important, will Tesla’s board do anything to rein in Mr. Musk?