The Australian sharemarket tumbled on Monday as investors brace for US President Donald Trump’s largest slew of tariffs yet, which could trigger a meaningful economic downturn.

The S&P/ASX 200 Index closed down 1.7 per cent, or by 138.6 points, to 7843.4, with about $41.6 billion of market value erased. The All Ordinaries also dropped 1.7 per cent as all 11 sectors fell into the red.

Brokers and strategists have warned of a volatile week for investors as America’s reciprocal tariffs are set to start on Wednesday, which has been dubbed by Trump as “liberation day”. Since the president directed officials in February to put together country-by-country tailored countermeasures, few details have emerged as to the size or substance of the incoming tariffs.

The unknowns have unsettled markets, leading to increasingly bearish forecasts on the global economy and major equity market losses. The ASX 200 suffered a 3.9 per cent loss over the first quarter – its worst start to the year since 2020.

On the back foot

Commsec chief economist Ryan Felsman said Monday’s losses had been compounded by fund managers rebalancing portfolios at the end of the quarter amid the broader sharemarket malaise.

“Sentiment is really on the back foot. There’s just a lack of good news for equities at the moment,” he said. “On top of that, all portfolio managers and index funds will be using the last day [of March] to rebalance.”

Technology stocks were heavily sold. Life360 dropped 5.5 per cent to $19.81 and Megaport was down 4.1 per cent to $9.63. That’s after the US’ technology-heavy Nasdaq index closed down almost 3 per cent lower on Friday with futures pointing to even further losses.

Commonwealth Bank helped moderate losses in the banking sector after turning positive, lifting 0.3 per cent in late trading to close at $150.93. But ANZ, National Australia Bank and Westpac were all in the red, falling between 0.4 per cent and 1.9 per cent.

Elsewhere, miners were a major drag on the ASX as a gloomy outlook for exports and falling iron ore prices compounded the risk-off sentiment. In Singapore, iron ore futures dropped 1.5 per cent to $US100.75 a tonne. Iron ore giant BHP shed 3.8 per cent to$38.20, Rio Tinto 4.5 per cent $115.49 and Fortescue 4 per cent to $15.37.

Lithium play Pilbara Minerals posted the biggest loss on the bourse, off 8.2 per cent to $1.69 a share.

Not even gold stocks were spared despite the precious metal – considered a haven asset – topping $US3100 an ounce on Monday afternoon. Northern Star Resources dropped 1.6 per cent to $18.32.

Stocks in focus

In corporate news, WiseTech edged up 1.5 per cent to $81.23 after it appointed two new non-executive directors including former chairman Andrew Harrison.

Qantas fell 3.6 per cent to $9.05 after announcing its long-standing director Todd Sampson was exiting as the airline completes its renewal process under chairman John Mullen.

David Di Pilla’s HMC Capital retreated 5.8 per cent to $6.23 after lobbing a takeover proposal for the country’s second-largest hospital group, Healthscope, after several weeks of legwork that included wedging itself into the target’s $1.6 billion debt stack.

And Orora advanced 4.4 per cent to $1.88 after clarifying that French regulators had engaged with its subsidiary Saverglass for an investigation into price increases. The probe followed complaints from the French beverage industry, including a “small number” of Saverglass customers.