In a letter to investors, Musk said he wouldn't sell more shares of his company in the near future and that he only sold recently to prepare for a possible recession.

I'm not selling anything for at least 18 to 24 months. Musk said in a chat on Thursday that there would be no stock sales until at least 25 years from now.

He said he needed to sell some stock to make sure there was enough powder for a worst case scenario.

This isn't the first time Musk has said he won't sell more stock. In August, Musk sold more than $8 billion worth of stock in the company to help finance his purchase of the micro-messaging service.

He sold another $3.6 billion in the company's stock. As of Thursday's close, the stock was trading at a 52 week low.

"From a long-term standpoint, there's a natural economic cycle that happens, and frankly, we'reoverdue for a recession," Musk said.

He said it's shocking that we haven't had an economic recession in a long time.

Some investors are concerned that Musk has become disengaged as the CEO of the company as he shifts his focus to leading the social networking site.

Musk said in the chat that he only sold his shares in the company because he's paranoid, and that there were no important meetings that he didn't attend.