Musician will.i.am revealed that he invested in Tesla before Elon Musk became CEO in 2008.He regrets turning down the chance to be an early backer of Airbnb due to his luxury hospitality standards.Tesla's stock has significantly increased since its IPO in 2010, with a record high of about $480 in December 2020.will.i.am previously invested in Twitter but sold his shares when co-founder Jack Dorsey left.