Tesla shares have fallen by 4.9% after Twitter users voted in favour of boss Elon Musk selling 10% of his stake in the carmaker in order to pay tax, BBC reported.
Musk polled his Twitter followers on whether he should sell the shares, and 58% of the 3.5 million accounts that voted said he should.
Musk held the poll over the weekend in response to a "billionaires tax" proposed by US Democrats.
Musk - who is one of the world's richest people - pledged that he would abide by the results of the poll, "whichever way it goes".
Musk has a large number of stock options which are due to expire next year. In order to exercise them, Musk would have to pay a large tax bill.
As of 30 June, Mr Musk's shareholding in Tesla came to about 170.5 million shares and selling 10% would amount to close to $21bn based on Friday's closing prices.