Dec 22 Reuters Tesla Inc shares are on track for their worst month ever as a selloff deepened on Thursday over worries about softening demand for electric cars and Chief Executive Elon Musk39;s distraction with Twitter.

The stock dropped almost 10 on Thursday to their lowest level since September 2020 after the automaker39;s website showed it was offering 7,500 discounts on Model 3 and Model Y electric vehicles delivered in the United States this month.

Tesla39;s stock has tumbled 36 so far in December, putting it on track for its worst ever monthly performance. By comparison, Tesla39;s shares dropped 22 in March 2020, when the coronavirus pandemic tipped financial markets into a tailspin.

Musk39;s 44 billion takeover of Twitter in October has been marked by chaos and controversy, with some investors questioning whether the billionaire is too distracted to properly run Tesla. Musk has also sold almost 40 billion worth of his Tesla shares this year, adding to pressure on the stock as investors worry he could sell more to keep Twitter afloat.

Moreover, Tesla in October said it expected to miss its vehicle delivery target this year, and analysts have worried that rising interest rates and a troubled economy could dent demand.

Tesla39;s stock market value stood at over 600 billion when it joined the SP 500 in December 2020, making it the sixth most valuable publicly listed U.S. company at that time. Since then, its market capitalization has shrunk to about 400 billion,…