New York - Wall Street has bled, with the S&P 500 sinking to its lowest since October 2014 as oil prices sank below $US30 per barrel and fears grew about economic trouble in China.
Pain was dealt widely, with Friday's trading volume unusually high and more than a fifth of S&P 500 stocks touching 52-week lows. The major S&P sectors all ended sharply lower. The Russell 2000 small-cap index dropped as much as 3.5 per cent to its lowest since July 2013.
The energy sector dropped 2.87 per cent as oil prices fell 6.5 per cent, in part due to fears of slow economic growth in China, where major stock indexes also slumped overnight. The energy sector has lost nearly half its value after hitting record highs in late 2014.
"Initially when oil was down, the convenient line was 'Well, it's good for the other nine sectors'," said Jake Dollarhide, chief executive officer of Longbow Asset Management in Tulsa, Oklahoma.
The Dow Jones industrial average dropped 2.39 per cent to end at 15,988.08 and the S&P 500 fell 2.16 per cent to 1,880.33. The Nasdaq Composite lost 2.74 per cent to 4,488.42.
For the week, the Dow fell 2.2 per cent, the S&P 500 lost 2.2 per cent and the Nasdaq dropped 3.3 per cent.
US stock exchanges will be closed on Monday in observance of Martin Luther King Jr Day, while China's equity markets will be open.
London - Britain's top share index has fallen to its lowest closing level in more than three years, hit by losses in commodity-related stocks as BHP Billiton suffered a major writedown and oil fell below a key level.
The blue-chip FTSE 100 equity index ended down 1.9 per cent at 5,804.10 points - its lowest closing level since late 2012.
The FTSE is some 20 per cent below a record high of 7,122.74 points reached last April and 7 per cent down since the start of 2016.
Concerns over China, the world's second-biggest economy and biggest consumer of metals, have hit oil and metals prices.
"This is a commodity-driven fall on the markets. Oil has gone below $US30, and that's added to fears. It's very difficult to call the bottom of this market," said Thames Capital Markets' trader Daniel Woodward.
Hong Kong - Asian shares have skidded to three-and-a-half-year lows.
Oil prices, which posted their first significant gains for 2016 on Thursday, came under fresh selling pressure on Friday as the prospect of additional Iranian supply loomed over the market.
Brent crude fell three per cent to $US29.86, heading for a weekly loss of more than 10 per cent. US crude fared even worse, sliding almost five per cent to $US29.75, and was set for a weekly decline of 10 per cent.
The collapse in oil prices has spooked financial markets as investors worry about the health of the global economy, with a slowdown in China and volatility in its markets making for a nervous start to the year.
"It's been another immensely volatile week," said Philip Shaw, chief economist at Investec in London.
The Shanghai Composite lost 3.5 per cent, while the CSI300 tumbled 3.2 per cent. That put the former on track for a nine per cent loss for the week, and the latter for a decline of 7.2 per cent.
Chinese shares extended their losses after data showed new yuan loans in December were well below the previous month's lending, and broad M2 money supply growth also slowed, with both missing expectations.
China will publish a host of data on Monday and Tuesday, including fourth quarter gross domestic product.
"It's another risk-off day," said Chris Scicluna, head of economic research at Daiwa Capital Markets.
"We had an awful session in Asia and that has spilt over into Europe."
Wellington - The S&P/NZX 50 Index climbed 59.81 points, or 1 per cent, to 6169.1.
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