Elon Musk's tweet that he is considering taking Tesla private has ignited a firestorm of speculation about how he could pull off such a deal. A leveraged buyout, as CNBC's Leslie Picker points out, seems infeasible since Tesla does not generate the cash flow necessary to pay out the debt. That leaves a take-private structure that primarily involves equity. The amount of money needed seems daunting. Some 170 million shares times $420 amounts to $71.4 billion. It would be the largest take-private transaction in history. But maybe he doesn't need to raise all that money. Maybe he just needs to get existing shareholders to believe in his vision, and drag in a few others. At least one minority stakeholder appears to be ruling itself out. Reuters reported on Saturday that Saudi Arabia's Public Investment Fund (PIF) has shown no interest so far in financing a deal, despite acquiring a minority stake in the company this year. However, the good news is Musk himself controls 20 percent of the stock. Let's look at the top five shareholders:

Tesla's largest shareholders

Elon Musk 20 percent T. Rowe Price 9.1 percent Fidelity 8.2 percent Baillie Gifford 7.7 percent Tencent 4.9 percent Source: FactSet After Musk, the four other largest shareholders own about 30 percent of the stock. That means Musk and the top four own 50 percent of Tesla. One Tesla investor, Saudi Arabia's Public If these four could be persuaded to stay in some kind of special-purpose entity, the goal is already a long way toward being met. Now, instead of raising $71 billion, he might need to raise only half of that, say, $35 billion or so. That's the thinking of Morningstar's David Whiston. In a recent note to investors, he speculated that "funding comes mostly from tech investors, such as possibly SoftBank or Tencent (the latter bought 5 percent of Tesla in 2017), sovereign wealth funds, and wealthy Silicon Valley investors." The good news, Whiston told CNBC last week, is that these kinds of strategic investors already exist. "The tech industry loves Elon," Whiston said. "I'd be surprised if SoftBank wanted nothing to do with the deal, and I'd be surprised if Tencent wasn't interested in buying more." Evercore ISI's George Galliers sees the same scenario, with equity from a combination of a strategic investor acquiring a 15 percent to 20 percent stake, two to three private investment firms or sovereign wealth funds acquiring up to 10 percent stakes, and finally certain larger members of the existing shareholder base or some form of fund for smaller accredited investors making up the rest. Bringing in strategic investors, private investment firms and sovereign wealth funds would greatly expand the pool of potential investors. How about a sovereign wealth fund? The reporting that Saudi Arabia's Public Investment Fund has invested roughly 3 percent ($2 billion) gives credence to this possibility. The dollar amount is less than 1 percent of the value of the Saudi PIF, and there would be plenty of room for other sovereign wealth funds to invest.

Sovereign Wealth Funds