In a flurry of trades executed Tuesday and Wednesday, the Tesla and SpaceX CEO offloaded about 4.4 million shares of his electric vehicle company.

The bulk of the CEO's sales were made on Tuesday, the filings showed. Tesla shares fell 12% that day, but edged higher on Wednesday by less than one percentage point.

As the filings became public, Musk wrote on Twitter, "No further TSLA sales planned after today." He made the remark in response to an account that heavily promotes Tesla stock, products and Musk on the social network.

CNBC reached out to Tesla and Musk to ask exactly how he plans to use the proceeds, and whether he sold more Tesla shares after April 27, the latest date on the filings out Thursday. They did not immediately respond to a request for comment.

Musk is bidding to buy Twitter and take the social media company private for $54.20 per share, around $44 billion total. In order to do so, Musk secured $25.5 billion of fully committed debt, including $12.5 billion in loans against his Tesla stock.

Twitter accepted his offer earlier this week, but the deal still requires shareholder and regulatory approval.

Musk would have to pay Twitter a termination fee of $1 billion if he fails to secure enough funding to complete his deal to buy the social media business, according to a regulatory filing out Tuesday.

On the other hand, Twitter would owe Musk a $1 billion break-up fee if it accepts a competing offer, or if shareholders reject the deal, according to the same filing.