Tesla chief Elon Musk announced he is considering taking the electric car and solar power company private, if indeed he was serious.

"Am considering taking Tesla private at $420," he tweeted, "Funding secured."  That's about a 20 percent premium higher than Tesla's current share price.  Now, that number - 420 - is kind of sketchy, because that's the number associated with marijuana culture.  So maybe Elon was having a laugh.

But in a statement to employees later released publicly, Musk expressed frustration with the demands of running a public company.

"As a public company, we are subject to wild swings in our stock price that can be a major distraction for everyone working at Tesla, all of whom are shareholders," he wrote, noting the pressures of dancing to the quarterly earnings cycle and the damage wrought by investors who are betting against the company.  "I fundamentally believe that we are at our best when everyone is focused on executing, when we can remain focused on our long-term mission, and when there are not perverse incentives for people to try to harm what we're all trying to achieve," the statement read.

And the announcement might have been a reaction to news earlier in the day that a Saudi investment group had taken a stake in the company, which sent shares soaring.  The Saudis bought less than five percent of the company in a deal assisted by JP Morgan.

"This has nothing to do with accumulating control for myself," Mr. Musk wrote.  "I own about 20 percent of the company now and don't envision that being substantially different after any deal is complete."

But it is clear that Elon prefers the working atmosphere at his privately held rocket company SpaceX, which he says is "far more operationally efficient".