Elon Musk is now 3 times as rich as Warren Buffett and worth more than the GDP of his home country of South Africa

• Bloomberg estimated Tesla CEO Elon Musk's net worth at $335 billion after Tesla's stock rose again.
• Tesla's stock has risen 65.6% this year, including an 8.5% gain on Monday.

Just days after Elon Musk became the first person to hit $300 billion in wealth, the Tesla CEO is now worth three times as much as the investing wizard Warren Buffett.

That's according to the Bloomberg Billionaires Index, which on Monday estimated the tech mogul's fortune at $335 billion after a $24 billion single-day gain. In comparison, the Berkshire Hathaway CEO Buffett was worth an estimated $104 billion.

Musk's wealth on the index is higher than the gross domestic product of his home country, South Africa, which totaled $301.9 billion last year, per data from the World Bank.

As tracked by Bloomberg, Musk's net worth has soared by $165 billion this year. His gains Monday were driven by an 8.5% rise in Tesla's share price, Bloomberg first reported. The multibillionaire owned about 22.4% of the company at the start of the year.

Last week, a 13% leap in Tesla's stock price netted Musk $36 billion - the largest single-day surge Bloomberg had ever recorded - after news emerged that the car-rental firm Hertz ordered 100,000 Teslas.

Musk, 50, now sits at a comfortable $142 billion above the world's second-richest man - Amazon's founder, Jeff Bezos, whose net worth Bloomberg puts at $193 billion.

Tesla's stock is up 65.6% this year, despite dips in March and May.

On Sunday, Musk tweeted that he was open to selling shares in the electric-car maker worth $6 billion to alleviate world hunger based on a plea from the director of the UN's World Food Programme.