The Australian sharemarket fell on Wednesday as Donald Trump ramped up his protectionist trade war, doubling down on threats to slap higher tariffs on copper imports as well as pharmaceuticals, prompting Federal Treasurer Jim Chalmers to announce he was “urgently” seeking more details from the US President.

The S&P/ASX 200 Index slipped 52.1 points, or 0.6 per cent, which was its biggest one-day fall in nine weeks, to close on Wednesday at 8538.6, its lowest level since June 27.

Seven of 11 sectors were in the red, paced by a sell-off in the copper producers, despite the fact sales to the US make up only a tiny fraction of Australia’s total copper exports.

Copper futures dropped as much as 2.4 per cent overnight after the US president said he would impose a 50 per cent tariff on copper within weeks.

Prices fell as low as $US9553.50 a tonne on the London Metal Exchange at the start of trade on Wednesday, but pared losses to trade down 0.4 per cent at $US9751.50 a tonne in early Asian trading.

Miners hit

On the ASX, the news hit Sandfire Resources which dropped 3.5 per cent to $11.18 and Capstone Copper, which fell 3 per cent to $9.28. Evolution, which produces both copper and gold, sank 7 per cent to $7.29.

“The copper stocks getting beaten up doesn’t make much sense – these guys don’t sell anything really to the US, it goes to China,” Hugh Dive, chief investment officer at Atlas Funds Management, told the Australian Financial Review.

“Trump could put a one million per cent tariff on copper, but if we don’t trade there, it doesn’t matter, it’s not going to impact earnings. It’s all theatre.”

BHP fell 1 per cent to $37.85, while Rio Tinto came off 0.6 per cent to $107.59. The ASX’s more diversified mining giants are expected to face a smaller hit on its exports from the Escondida mine they jointly own in Chile, which is the world’s largest producer of copper concentrates and cathodes.

Trump also flagged he could offer pharmaceutical manufacturers at least a year before applying a 200 per cent tariff on their foreign-made products. Chalmers on Wednesday said the developments were concerning and that he was “urgently” seeking more detail. CSL edged 0.9 per cent lower on the news to $243.71.

Gold miners also sank as bullion traded near $US3300 an ounce, after a 1 per cent loss in the previous session. Newmont tumbled 5.4 per cent to $87.46, Northern Star, which was downgraded to “neutral” on Tuesday, 3.4 per cent to $16.37, and Perseus 2.3 per cent to $3.45

“A fifth day of gains for US yields weighed on the price of bullion and gold stocks,” said IG market analyst Tony Sycamore.

Elsewhere on the ASX, interest rate-sensitive property stocks moved lower after the Reserve Bank shocked the market with a decision to keep the cash rate at 3.85 per cent. Goodman Group was down 2.6 per cent to $34.03, Stockland 1.5 per cent to $5.44, and Mirvac 0.9 per cent to $2.18.

Stocks on the move

In corporate news, Lifestyle Communities plunged 37.2 per cent to $4.42 after a landmark tribunal decision that found its lucrative deferred management fees, or exit fees, charged to residents were invalid under state tenancy laws.

Orica lifted 2.9 per cent to $20.40 on news it had appointed outgoing Boral chief executive Vik Bansal to become its next chairman.

Telix Pharmaceuticals leapt 5.6 per cent to $25.39 after announcing its prostate cancer imaging agent was granted a permanent insurance code by the US Medicare and Medicaid system.

Bega Cheese came off 1.5 per cent to $5.21 following the announcement it would close its loss-making peanut processing company.

And A2 Milk dropped 4.1 per cent to $7.30 after Citi cut its outlook to “neutral”, with a short-term share price target of $8.20.