The electric-car maker's chief executive officer tweeted earlier this month that he only has one house in the San Francisco Bay area that is rented out for events, and that if he sold, it "would see less use, unless bought by a big family, which might happen some day."

Musk, 49, first announced plans more than a year ago to sell his homes and most of his possessions as a way to blunt criticism of his wealth. Within days, he put two of his California properties on the market.