The world’s richest man is selling billions of dollars worth of stock in the electric car company he created and runs, in preparation to buy social media company, Twitter.

According to filings with the Securities and Exchange Commission, Elon Musk offloaded a total of 4.4 million Tesla shares on April 26th and 27th, worth an estimated $4 billion, which was followed by an additional 5.2 million shares on Thursday, bringing the total to around $8.5 billion.

The move comes as Musk prepares to buy Twitter for $44 billion, an announcement that caused Tesla to drop in value by $275 billion earlier in the month. The shares rose back up by 3.2 percent when the markets opened on April 29th.

According to reports, Musk made an arrangement with Morgan Stanley and several other lenders for $25.5 billion of debt and margin-loan financing. Tens of billions of dollars of his own stock in Tesla, as well as $21 billion worth of equity, would make up the remainder of the purchase price, a financial plan which alarmed some investors of the electric car company.

The billionaire Tweeted on April 28th that there would be no further stock sales planned “after today”, implying that there could have been more sales that would be reported the following day, although we can’t confirm this.

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The Los Angeles Times says The deal will be one of the largest leveraged buyouts in history, and in certain circumstances, the lenders could face up to $1 billion in termination fees if the deal falls through, so the risks aren’t exclusive to Musk.

Musk began selling his stake in Tesla for the first time six months ago, with a sale of $16 billion worth of stocks. The sale caused a drop in the price of the stock, which cut $18 billion from his net worth, despite the brand reporting unexpectedly high earnings recently. The recent sale brings the total value of stocks sold up to $20 billion.

Musk has been the majority shareholder of Tesla since 2008, and the instability of Tesla stock amid its CEO’s desire to own Twitter highlights how closely tied his actions are to the value of the company.

Musk had said that investors in the social media would receive $54.20 per share of stock, but Twitter shares close short of that number at $49.11 on April 28th.