Elon Musk sold around $8.4 billion worth of Tesla shares this week as he moved to buy Twitter

Elon Musk sold roughly $8.4 billion worth of Tesla shares this week, following his bid to take Twitter private, according to filings with the Securities and Exchange Commission.

The Tesla and SpaceX CEO offloaded about 4.4 million shares of his electric vehicle company in trades on Tuesday and Wednesday. New filings on Friday showed sales of an additional 5.2 million shares on Thursday.

The first of the CEO's sales were made on Tuesday, the filings showed. Tesla shares fell 12% that day. Shares of Tesla were up about 2.5% on Friday.

As the filings became public on Thursday night, 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.

— CNBC's Lauren Feiner contributed to this report.