Some of the world's richest people have had billions of dollars shaved off their fortunes after the Dow Jones industrial average took an ugly nosedive this morning.

The Dow plunged 1,175.21 points, or 4.6 per cent, as stocks took their worst loss in six and a half years.

Three of the top five richest people in the world - Warren Buffett, Mark Zuckerberg and Jeff Bezos - lost a combined US$12.1 billion ($16.6b) in a single day, according to Forbes.

Berkshire Hathaway chairman and CEO Warren Buffett was hit the hardest. The drop shaved US$5.3b, or nearly 6 per cent, off his net worth.

Advertisement

Berkshire Hathaway, which owns roughly 488.5 million shares, or 9.92 per cent, of Wells Fargo, lost more than US$2.4b after the US banks' shares plunged more than 7 per cent, according to Business Insider.

According to Forbes real time billionaire rankings, Buffett is still the third richest person in the world with a net worth of US$84.6b.

Facebook co-founder and CEO Mark Zuckerberg was the next biggest casualty, losing US$3.6b, or 4.7 per cent, of his net worth after shares in his social media company dropped 5 per cent.

Zuckerberg finished the day with US$73.1b to his name, but dropped outside the top five richest people in the world, according to Forbes.

The world's wealthiest person, Amazon founder and CEO Jeff Bezos, saw his fortune drop US$3.2b.

Despite the drop, Bezos is still worth a staggering US$115.7b, US$25b ahead of the second richest person Bill Gates, according to Forbes.

Others who suffered billion-dollar losses include Google co-founders Larry Page and Sergey Brin who each lost US$2.2b after shares in their parent company, Alphabet, fell by 5 per cent.

Oracle founder Larry Ellison also saw his fortune drop US$2.2b.

Advertisement

Combined, these six men lost a whopping US$18.8b, according to Forbes.

Many of the world's richest people have their net worth tied up in shares of their publicly-traded companies, making them vulnerable to fluctuations in the market.

Australian Treasurer Scott Morrison believes the big dive on the US stockmarket is a recalibration associated with recent economic data.

"Markets are volatile - when they recalibrate in relation to events like this you do see a bit of these events happening," he said. "But people who watch these markets more and participate in them more closely than I do, I think, will see this for what it is and understand the forces behind it."

Key equity markets in the US, Europe, Britain and Asia — bar China — all declined sharply, with Wall Street the worst performer.

US stocks have been under pressure for the last week as investors weigh the risks of more Federal Reserve interest rate hikes following strong economic data.

Britain's FTSE 100 lost 1.5 per cent while France's CAC 40 slid 1.5 per cent. The DAX in Germany shed 0.8 per cent. Japan's benchmark Nikkei 225 tumbled 2.6 per cent and the South Korean Kospi shed 1.3 per cent. Hong Kong's Hang Seng index sank 1.1 per cent.

The Standard & Poor's 500 index, the benchmark most professional investors and many index funds use, skidded 113.19 points, or 4.1 per cent, to 2,648.94. That was its biggest loss since August 2011, when investors were fearful about European government debt and the US came close to breaching its debt ceiling.

The Nasdaq composite fell 273.42 points, or 3.8 per cent, to 6,967.53. The Russell 2000 index of smaller-company stocks sank 56.18 points, or 3.6 per cent, for 1,491.09.

As bad as Monday's drop is, the market saw worse days during the financial crisis. The Dow's 777-point plunge in September 2008 was equivalent to 7 per cent, far bigger than today's decline.