Tesla Inc Chief Executive Elon Musk sold another 934,091 shares of the electric vehicle maker worth $1.05 billion after exercising options to buy 2.15 million shares, U.S. securities filings showed on Tuesday.

The world’s richest person had on Nov. 6 tweeted that he would sell 10% of his stock if users of the social media platform approved. A majority of them had agreed with the sale.

Since then, he has sold 9.2 million shares worth $9.9 billion. Last Tuesday, Musk sold 934,091 shares to meet tax withholding obligations related to the exercise of stock options.