Elon Musk's net worth tops $400 billion, a first for any person. Here's where he gets his wealth.

Tesla CEO Elon Musk has become the first person to top a net worth of $400 billion, according to Bloomberg News.

Musk's wealth, which was last counted at $384 billion by the Bloomberg Billionaires Index, jumped after an insider share sale of SpaceX, the space exploration company that he founded. According to Bloomberg, the sale boosted Musk's net worth by about $50 billion, bringing his current net worth to $429.2 billion. 

The world's second wealthiest person, Jeff Bezos, is worth $244 billion, Bloomberg Billionaires Index shows.