Elon Musk has sold more than 4 million shares of Tesla stock worth roughly $4 billion, most likely to help fund his $44 billion purchase of Twitter.

Musk reported the sale in a filing with the Securities and Exchange Commission on Thursday.

The shares were sold over the past few days, at prices ranging from $872.02 to $999.13.

The world’s richest man tweeted that no further sales of Tesla shares are planned.

Most of the sales took place on Tuesday, when Tesla shares closed down 12%.

Tesla investors have also sold shares this week, as they worry that Musk will no longer focus on the company now that he’s bought Twitter.