Twitter's new owner and Tesla CEO Elon Musk has sold nearly $4 billion worth of Tesla shares, according to regulatory filings.

Musk, who bought Twitter for $44 billion, sold 19.5 million shares of the electric car company from Nov. 4 to Nov. 8, according to Tuesday's filings with the Securities and Exchange Commission.

He sold $7 billion of his Tesla stock in August as he worked to finance the Twitter purchase he was trying to get out of at the time. In all, Musk has sold more than $19 billion worth of Tesla stock since April, including those in Tuesday's filings, likely to fund his share of the Twitter purchase.

Most of Musk's wealth is tied up in shares of Tesla Inc. On Tuesday, his personal net worth dropped below $200 billion, according to Forbes, but he is still the world's richest person.

Musk had lined up banks including Morgan Stanley to help finance the Twitter deal. His original share of the deal was about $15.5 billion, Wedbush Analyst Dan Ives estimated . But if equity investors dropped out, Musk would be on the hook to replace them or throw in more of his own money.

Tesla's shares closed down $5.78, or 2.9%, at $191.30. The stock has lost 52% of its value since the start of this year. In comparison, the S&P 500 index has lost about 20% of its value so far this year.