Tesla and SpaceX CEO Elon Musk jumped past Bill Gates to become the second richest person on the planet, according to the Bloomberg Billionaire Index. Musk is worth $128 billion, with Amazon boss Jeff Bezos still holding the top spot at $182 billion.

The index rounds each person's worth up to the nearest billion, so Musk is actually worth $127.9 billion compared to the Microsoft co-founder's $127.7 billion. Gates lost his spot partially as a result of his philanthropic effort -- he's given more than $27 billion to the Gates Foundation since 2006, Bloomberg noted.

Last week, Musk snatched the No. 3 spot from Facebook's Mark Zuckerberg (he was fourth in August). His rise comes after Tesla shares surged in the wake of news that the electric car company will be admitted to the S&P 500 index next month, CNBC reported Tuesday.

Tech billionaires make up seven of the Top 10 -- Google co-founders Larry Page and Sergey Brin are worth $81.3 billion and $78.7 billion respectively, while former Microsoft CEO Steve Ballmer has $76.1 billion.

By: Sean Keane