CEO of Tesla Motors Elon Musk reacts following the company’s initial public offering at the NASDAQ market in New York June 29, 2010Brendan McDermid | ReutersTesla co-founder Elon Musk is now the world’s second richest person after he leapfrogged Microsoft billionaire Bill Gates on the Bloomberg Billionaire Index, which tracks the wealth of the world’s 500 richest people.The 49-year-old entrepreneur, who is also the co-founder of space exploration firm SpaceX, saw his net worth rise by $7.2 billion to $128 billion on Monday as Tesla shares surged following the news that the electric car company will be admitted to the S&P 500 index in December.Musk’s net worth has risen by $100.3 billion in 2020, marking the largest increase among those on the Bloomberg Billionaire Index. In January, Musk ranked 35th on the list.Last week, Musk pushed Facebook CEO Mark Zuckerberg down into fourth position when he claimed the third spot.The only person ahead of Musk now is Amazon boss Jeff Bezos, who took the top spot from Gates in 2017 and has stayed there since.The move forces Gates down into third place, marking only the second time in the index’s eight-year history that he hasn’t been ranked in the top two. It’s worth noting that Gates’s net worth of $127.7 billion would be considerably higher if it weren’t for the philanthropic endeavors he has become known for. Since 2006, he has given over $27 billion to the Bill Gates Foundation.This year, those on the Bloomberg index have collectively added 23%, or $1.3 trillion, to their net worth. Meanwhile, millions of workers are facing financial hardship after being laid off by their employers due to the ongoing coronavirus pandemic.