By Anirban Sen

(Reuters.) Speculations among investors about Elon Musk’s $44 billion purchase of Tesla are afoot Twitter Inc (NYSE:) Wednesday saw the shares of the social media company fall to the lowest point since two days before the announcement.

Traders were concerned that Musk may not be able to raise $21 billion in cash and might decide to sell Tesla Inc shares.

Before, he has retreated. He refused to accept a position on Twitter’s board earlier in the month. Musk claimed that $72B was available for Tesla’s privatization, in 2018, but he did not respond to an offer.

Musk will also have to pay a 1 billion breakup fee, which is a small fraction of Forbes’ $240 billion fortune. This would allow him to exit the deal.

Chris Pultz at Kellner Capital, portfolio manager for merger arbitrage said that there is a lot more risk than the deal can be completed in the coming six months.

Musk representatives didn’t immediately reply to our requests for comment.

Twitter shares closed in New York at $48.68. This is a significant discount from the $54.20 price. According to Reuters calculations, there’s a 62% chance that the deal will be completed. Investors said that this is a low likelihood of the deal being completed, considering it unlikely Musk would be subject to antitrust scrutiny.

Tesla shares plunged more than 12 percent on Tuesday. This was in spite of concerns that Musk may have to sell his shares to cover the $21 billion equity payment in the Twitter deal.

Musk might be able calm the markets by sharing details about his equity financing source or inviting other partners to share the checks. Some fund managers warned that this would pose risks because of the identity and nature of the partners.

Roy Behren is the managing member at Westchester Capital Management. The company has assets totalling $5.4 billion and Roy said that the $1 billion termination fee did not make Musk reconsider leaving the deal.

Behren explained that the fees are lower when compared to Behren’s net worth and transaction size.