Elon Musk assures Tesla worrywarts he isn't going anywhere

The big news the Financial Times got out of Elon Musk at its Future of the Car summit was decidedly unrelated to cars. The billionaire planning to take over Twitter said he would reverse the platform's permanent ban of former President Donald Trump.

But Tesla's chief executive officer also made plenty of headline-worthy comments about the world's most valuable auto company. Musk said he'll stay at Tesla "as long as I can be useful," assuaging concern that a foray into social media will compromise the amount of attention the world's richest man devotes to his electric car company. Tesla has long been clear that it's highly dependent on Musk, who's been CEO since 2008...