Trump debate comments freak out investors, wipe $41b from All Ords

US President Donald Trump freaked out Australian investors when he signalled the election result could be long and painful.

The Australian sharemarket has seen its first monthly decline since March after US President Donald Trump freaked out investors during his first debate with Democratic presidential candidate Joe Biden.

The S&P/ASX200 plunged 2.29 per cent to 5815.9, while the All Ordinaries Index tumbled 2.15 per cent to 6009.3.

CommSec analyst James Tao said about $41 billion was wiped off the All Ords, leaving the bourse down 4 per cent for the month and 1.4 per cent for the quarter.

“The silver lining is we had five straight months of gains and it’s better than the fall of about 21 per cent in March,” Mr Tao said.

ThinkMarkets Australia analyst Carl Capolingua said the bourse opened lower after uninspiring overnight leads, while the stronger Aussie dollar was undermining some overseas earners like miners and healthcare heavyweight CSL, which fell 2.89 per cent to $287.

The market was transfixed by the debate from around 11am AEST, tracking higher as it wore on and paring back about half of the losses, with not too much in there to rattle investors.

“And then President Trump started talking about stationing supporters at ballot boxes to essentially forcefully oversee the voting process,” Mr Capolingua said.

“He said he wouldn’t accept a result which he considered to be tainted.

US President Donald Trump spooked investors by signalling at the first presidential debate the election result could be a long way off. Picture: Olivier Douliery/AFP

“The impact on the futures was almost instantaneous. It knocked about 80 points off the ASX200 in just over an hour. Everything suddenly turned red and just stayed there.

“What we don’t want to see is a long and drawn-out disputed result. Based upon the comments from President Trump today, that prospect just ratcheted up.”

Among the miners, South32 fell 5.56 per cent to $2.04, BHP dropped 3.5 per cent to $35.60 and Rio Tinto shed 1.57 per cent to $94.32, but Fortescue bucked the trend, adding 0.87 per cent to $16.30.

Energy stocks slumped after the oil price fell more than 3 per cent overnight.

Origin was down 4.87 per cent at $4.30, Woodside gave up 4.9 per cent to $17.58 and Santos backtracked 3.94 per cent to $4.88 despite its controversial Narrabri coal seam gas project in NSW getting final approval to proceed subject to conditions.

ANZ backtracked 2.05 per cent to $17.22, Commonwealth Bank slid 2.17 per cent to $63.61, National Australia Bank eased 1.83 per cent to $17.75 and Westpac declined 1.86 per cent to $16.84.

Corporate Travel Management was a rare bright spot, gaining 6.62 per cent to $17.23 after emerging from a trading halt and announcing the acquisition of a complementary US business.

The Aussie dollar was fetching 71.12 US cents, 55.39 British pence and 60.61 Euro cents in afternoon trade.