Twitter Inc TWTR shares are up 30.4% this week after Tesla Inc TSLA CEO and world's richest man Elon Musk disclosed a new 9.2% ownership stake in Twitter and announced on Tuesday joined Twitter's board of directors.

Musk tweeted he is already "working with [Twitter CEO Parag Agrawal] & Twitter board to make significant improvements to Twitter in coming months!"

Buyout In Play: While Twitter investors wait on the edge of their seats to see exactly what changes Musk has in store for the platform, Whitney Tilson said Musk's ownership stake in Twitter likely means a full Twitter buyout is inevitable.

"Musk has now put Twitter into play, meaning that someone is going to buy this company. The questions are who and at what price?" said Tilson, the former hedge fund manager and current CEO of Empire Financial Research.

He noted the most obvious potential buyers include big tech companies that have mountains of cash to spend, such as Meta Platforms Inc FB, Microsoft Corporation MSFT or Alphabet, Inc. GOOG GOOGL. But, Tilson said all three of these potential buyers are likely out of the running for a Twitter takeover on antitrust grounds.

At the same time, he said there's no way the U.S. government would let a foreign company buy Twitter, which further narrows the field of potential buyers.

Most Likely Buyers: Tilson said the shortlist of potential Twitter buyers includes companies such as salesforce.com, inc. CRM or Oracle Corporation ORCL. He also said PayPal Holdings Inc PYPL is a potential buyer after it recently made an unsuccessful bid for social media platform Pinterest Inc PINS.

"But I think the most likely scenario is that Twitter is purchased by a private equity firm, with Musk's participation," Tilson said.

As far as a buyout price Tilson said it would likely be "much higher" than Twitter's current market price and he believes the stock is still a "strong buy" after this week's rally.

Benzinga's Take: During Musk's term on the board, he is prohibited from being the beneficial owner of more than 14.9% of Twitter's common shares. However, Musk has a history of ignoring rules and regulations, and has certainly shown he's not afraid to defy the SEC or any other government entities if they try to stop him from getting what he wants.