On Tesla's fourth-quarter earnings call, CEO Elon Musk said the company is ending production of its Model S and X vehicles.

Elon Musk said Tesla Inc. needs to build and operate what he is calling a “TeraFab” to manufacture semiconductors, a massive undertaking that will cost billions of dollars and mark another expansion beyond what had been the company’s core electric vehicle business.

For the fourth quarter of last year, Tesla’s net income also plunged, down 61% to $840 million, or 24 cents. Excluding one-time charges, net income totaled 50 cents per share, compared to analysts’ forecasts of 45 cents.

The company announced it was ending production of its higher-end Model S and Model Y, and turning that production space over to making humanoid robots.

Investors are seeking more clarity Wednesday on how the company will meet CEO Elon Musk's ambitious timeline for robotaxi expansion. Tesla is set to be a major player in the U.S. autonomous-vehicle market,