Elon Musk is now the richest man on the planet, overtaking Jeff Bezos

Amazon founder Jeff Bezos is no longer the richest man in the world, after Tesla CEO Elon Musk's fortune on Thursday rose to $188.5 billion, $1.5 billion more than Bezos.

Shares in electric carmaker Tesla rose by more than 6 percent on Thursday to push South African-born Musk into the top spot, dethroning Bezos from the place he has occupied for more than three years, according to the Bloomberg Billionaires Index.

Tesla's market capitalization, a measurement of the company's stock price multiplied by its number of shares, has been on a tear since the beginning of last year, rising from about $80 billion in January 2020 to just over $760 billion today. Musk's personal fortune, which is tied to Tesla's share price, rose by more than $150 billion last year.

The new valuation is more than eight times the combined values of the traditional "Big Three" U.S. automakers, GM, Ford and Fiat Chrysler.

In November, Musk leapfrogged past Microsoft co-founder Bill Gates to become the world's second-richest man, with $128 billion at that time. Musk's massive personal fortune comes mostly from owning 20 percent of Tesla and 54 percent of his space transportation company SpaceX.

Tesla joined the S&P 500 in December, increasing trading volume and volatility as the size of its market cap forced investors to rebalance their portfolios to compensate for its weight in the index.

Meanwhile, Amazon's shares have dipped from their September high of about $3,500 to roughly $3,200 as investors sell off anticipating the incoming administration under President-elect Joe Biden will tighten tech regulation and cut into profits for the online retail giant.

Musk's cryptic and off-center tweets have done little to diminish investor interest from reaching new highs and have instead inspired passionate fandom from online followers who tout the stock on message boards and invest using direct-to-consumer trading apps like Robinhood, where it is one of the most popular equities to hold.

Neither has the consensus from traditional Wall Street analysts whose median target for Tesla is about $450 per share, nearly half of its present value.

The U.S. gained 56 new billionaires between March and December last year, according to the Institute for Policy Studies, bringing the total to 659. Their wealth jumped by more than $1 trillion in the months since the pandemic began.