The Australian share market suffered its biggest loss since December 10, with every sector deep in the red after signs that China is striking back against the US in their escalating trade war.
The benchmark S&P/ASX200 index finished down 128.3 points, or 1.9 per cent, to 6,640.3 points on Monday, while the broader All Ordinaries was down 135.5 points, or 1.98 per cent, to 6,710.6 points.
It was the S&P/ASX200's worst loss since a 129-point, 2.3 per cent loss on December 10, 2018.
The market was steadily lower throughout the session and closed very close to the day's lows.
The plunge came after China let the yuan tumble to its weakest level in a decade and asked state-owned companies to suspend US agricultural imports, in apparent retaliation for US President Donald Trump's vow to impose additional 10 per cent tariffs on Chinese exports on September 1.
The Australian dollar slid 0.45 per cent to 67.71 US cents, from 68.45 US cents on Friday, its lowest level against the greenback since 2009.
The Aussie has declined 4.3 per cent in the last two-and-a-half weeks, having bought 70.75 US cents on July 18.
The tech sector had the worst losses on Monday, declining 5.2 per cent as a whole in its worst day since it declined 7.8 per cent on August 11, 2010.
Machine learning dataset company Appen was the worst-performing ASX200 component, losing 10.6 per cent to hit a nearly two-month low of $26.87, while Afterpay Touch fell 7.8 per cent to a five-week low of $23.50, and logistics software company WiseTech Global plunged 8.1 per cent to a one-month low of $29.30.
The big banks were in the red, with Westpac down 1.2 per cent to $28.47, Commonwealth down 0.8 per cent to 81.21, ANZ down 1.7 per cent to $27.31 and NAB down 1.3 per cent to $28.15.
In the heavyweight mining sector, BHP dropped 3.6 per cent to $37.38, Rio Tinto was down 3.5 per cent to $91.49, South32 fell 4.0 per cent to $2.86 and Fortescue Metals was down 7.2 per cent to $7.09.
Major goldminers Newcrest and Northern Star were down 1.0 per cent and 1.3 per cent, respectively, but smaller goldminers were among the few companies to post gains, as the price of the yellow metal rose 0.5 per cent to hit another multi-year high.
Against the US dollar, gold was selling for $US1,456 an ounce, its highest level since early 2013, and against the Australian dollar it was at $A2,145 an ounce, its highest level ever.
Evolution Mining gained 1.9 per cent, Resolute Mining was up 4.3 per cent, and Dacian Gold was up 7.3 per cent.
Oil Search was up 2.8 per cent to $7.14 after cabinet ministers in Papua New Guinea agreed to stand behind a controversial liquefied natural gas deal with a consortium that includes Oil Search.
Wesfarmers gained 0.8 per cent to $39.16 after the competition watchdog said it would not stand in the way of the Kmart and Target owner's $230 million acquisition of deals website operator Catch Group.
Cryptocurrencies were buoyant, with bitcoin up 9.1 per cent to $US11595 or $A17,075 on Sydney exchange the Independent Reserve.
In all, though, losses were the order of the day, with property trusts - down 0.7 per cent - the only sector not to decline at least a percentage point.
The Reserve Bank of Australia is also set to announce its latest decision on interest rates on Tuesday afternoon, with traders giving about a 50-50 chance of third rate cut.