Tesla CEO Elon Musk sold nearly $4 billion worth of stock in the electric car company, a filing with the US Securities and Exchange Commission showed on Tuesday, as he completed a $44 billion takeover of Twitter after many weeks.

Musk used Tesla stock to fund most of his Twitter purchases, and he sold more than 19 million shares worth more than $3.9 billion, SEC filings show.

In late October, Musk took control of Twitter and fired its executives after a back-and-forth between the world’s richest man and the influential social media company.

Shortly after accepting his unsolicited offer in April, he tried to back out of the Twitter deal and said in July he would cancel the contract because he was misled by Twitter about the number of false “bot” accounts — allegations the company rejected.

After Musk tried to terminate the deal, Twitter filed a lawsuit asking the entrepreneur to participate in the deal. But as the trial loomed, he surrendered and resumed his takeover plans.

Musk’s decision to take Twitter out of the stock market allowed him to make big changes quickly, but it also left the company mired in more debt, a risky choice for a money-losing business.

In early November, he announced an $8 monthly fee to verify users’ accounts, believing the plan would solve the platform’s problems with bots and trolls while creating a new revenue stream for the company.