Elon Musk has launched a campaign to take Tesla private on a day that included several provocative tweets, a suspension (and resumption) of trading in the company’s shares, reports of a significant Saudi investment, a surge in stock price, and an evocative, Musk-tinged appeal to the Tesla faithful: “The future is very bright and we’ll keep fighting to achieve our mission.”

The ride started with Tesla’s stock rising more than 7% after Musk tweeted he was “considering taking Tesla private” and had funding in place to do so at a price of $420 (£325) per share. Shortly afterwards, Tesla published a blogpost written by Musk entitled ‘Taking Tesla private’ that had been sent to all employees.

Elon Musk (@elonmusk) Am considering taking Tesla private at $420. Funding secured.

The tweet appeared to be triggered by a report in the Financial Times that Saudi Arabia has built up a stake in Tesla worth up to $2.9bn.

At $420 a share, Tesla would have an enterprise value of about $82bn including debt, well above its stock market value, which reached $63.8bn on Tuesday. Shares closed up 11% at $378. To take Tesla private, Musk would have to pull off the largest leveraged buyout in history, surpassing Texas electric utility TXU’s in 2007. Analysts say Tesla doesn’t fit the typical profile of a company that can raise tens of billions of dollars of debt to fund such a deal.

In a follow up tweet, Musk wrote: “I don’t have a controlling vote now and wouldn’t expect any shareholder to have one if we go private. I won’t be selling in either scenario.”

In the letter sent out to Tesla employees, Musk did not say that Tesla had secured funding. He wrote instead that “a final decision has not yet been made, but the reason for doing this is all about creating the environment for Tesla to operate best”.

Musk described the “wild swings” in Tesla’s stock price as a “major distraction” and said the quarterly earnings cycle puts “enormous pressure on Tesla to make decisions that may be right for a given quarter, but not necessarily right for the long-term”.

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But Musk rejected the interpretation that he was simply seeking greater wealth or control of the company than the 20% he already owns. He wrote: “Basically, I’m trying to accomplish an outcome where Tesla can operate at its best, free from as much distraction and short-term thinking as possible.”

Saudi Arabia’s public investment fund (PIF), which invests its vast oil wealth, has quietly built up a stake of between 3% and 5% in the company, according to the FT. The investment would not have emerged until now because stakes of less than 5% do not need to be disclosed to the stock market.

PIF, which manages more than $250bn in assets, reportedly made an overture to Musk earlier this year, offering to invest money in the company in return for new shares.

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Tesla ignored the approach, prompting PIF to begin acquiring shares in the company through stock markets, with the assistance of JP Morgan.

Analyst Gene Munster, a managing partner at venture capital firm Loup Ventures, told Bloomberg: “Elon Musk does not want to run public companies. His missions are big and make it difficult to accommodate investors’ quarterly expectations. Our guess is there is a one-in-three chance he can actually pull this off.”

No Wall Street bank contacted by CNBC said it was aware of any transaction or had any knowledge of commitment to funding a leveraged buyout of Tesla.

The Securities and Exchange Commission (SEC) also declined to comment on the matter.

The confusion increased speculation that Musk was engaged in a stunt – which could backfire if Musk is found to have violated fiduciary directives governing how senior executives at publicly-held companies are permitted to release information that could affect a firm’s stock price.

In 2013, the SEC ruled that companies are allowed to use social media outlets like Facebook and Twitter to announce news. But many thought Musk could be making a pun by twice tweeting “420” – an abbreviation of 4/20, code for the consumption of cannabis.

Musk’s fondness for making statements via Twitter has backfired in the past. He attracted furious criticism after baselessly calling a British diver who helped rescue the boys trapped in a flooded cave in Thailand a “pedo”. Tesla’s share price dropped and Musk was forced to apologise.