Benchmark U.S. crude fell 83 cents, or 1.7 percent, to $48.73 a barrel on the New York Mercantile Exchange.
The S&P/TSX composite index fell 143.08 points to 15,074.25, with almost all of its sectors moving lower.
This week has been its biggest rise since June 2016. "If it's North Korea, I don't think this will be a fruitful period for equity investors", Nick said. "What we're seeing today is political tensions over North Korea and the United States. making people nervous", said Robert Pavlik, chief market strategist at Boston Private Wealth in NY.
A Labor Department report showed its producer price index posted a surprise drop in July, down 0.1% for the largest slide in nearly a year.
US Treasury yields fell on Wednesday, with yields on the benchmark 10-year note hitting a six-week low, as investors reached for safe-haven assets such as government debt.
Shares of Macy's tumbled 8.3 percent and Kohl's 7.3 percent after the department store operators reported a drop in quarterly same-store sales that stoked concerns that their turnaround may still be a long way off.More news: Kristen Bell and Dax Shepard: We go to couple's therapy
"Generally, earnings are good, .it's our view that this pullback (in stocks) should provide good buying opportunities", ABC Funds' Michael said.
High-flying technology names suffered outsized losses on the day, with Apple falling 3.2 per cent, Amazon 2.6 per cent and Facebook 2.2 per cent. Biotech companies Celgene and Amgen lost 3.8 per cent and 2.6 per cent, respectively.
If the North Korean regime "does anything" to the U.S. or a USA ally "things will happen to them like they never thought possible", he told reporters on Thursday, according to Bloomberg.
SIMMERING TENSIONS: North Korea revealed on Thursday a detailed plan to launch a salvo of ballistic missiles toward the U.S. Pacific territory of Guam, a major military hub and home to U.S. bombers. Eastern time. The Dow Jones industrial average slid 120 points, or 0.5 percent, to 21,928.
The S&P 500 has hadn't a single day move of more than 0.5 percent since mid-July and has fallen more than 1 percent only twice this year. Futures on the S&P 500 Index (SPX) and Nasdaq-100 Index (NDX) are lower, as well, in what could be a third straight loss for US stocks. Copper fell 2 cents to $2.90 a pound. But some investors welcomed the dip in the sector, which has been S&P's leading gainer so far this year.
"Since these are the stocks that have been in the spotlight the most, they tend to have the most volatility upwards and downwards", said Chris Bertelsen, chief investment officer of Aviance Capital Management in Sarasota, Florida.More news: Google celebrates history of hip hop with doodle that lets you DJ
METALS: Gold, a traditional safe haven play, added $16.70, or 1.3 percent, to settle at $1,279.30 an ounce.
Gold prices continued to rise after North Korea state media warned its missiles could surround the USA territory of Guam in an "enveloping fire" in coming weeks.
Emerging market stocks lost 0.89 per cent. MSCI's broadest index of Asia-Pacific shares outside Japan closed 0.57 per cent lower.
Declining issues outnumbered advancing ones on the NYSE by a 2.29-to-1 ratio; on Nasdaq, a 2.47-to-1 ratio favoured decliners.
Data from the U.S. Commodity Futures Trading Commission released last week showed that currency speculators still held a large net short position in the yen during the week ended August 1, although somewhat smaller than the levels seen a couple of weeks earlier, when their bearish bets against the yen grew to the largest since January 2014.More news: 'I like Mourinho a lot' - Willian reveals failed move to Man Utd
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