The S&P/ASX200 fell 24.9 points on Friday, down 0.27 per cent, to 9,058.9, as the broader All Ordinaries lost 28.8 points, or 0.31 per cent, to 9,269.7.
The top 200 has dropped almost 2.5 per cent since resetting record highs earlier in August after housing market concerns sparked a banking sell-off that has loomed large over earnings season.
Energy and gold stocks offered some support as oil prices climbed and historically high US debt and Treasury yields rattled investors, prompting the US government to intervene in its roughly $US60 trillion ($A84 trillion) bond market.
The move was concerning and echoed interventions that preceded 1992's Black Wednesday pound crisis and 2015's Swiss Franc shock, Moomoo market strategist Michael McCarthy said.
"It appears that we regularly need to repeat the lesson that nobody is bigger than the market," he told AAP.
"In both of those cases, the governors of the Bank of England and the Swiss National Bank tried to hold back the tide, and eventually they got washed away by it.
"What happened this week has increased the likelihood that the next financial crisis will originate in the US bond market."
Caution was the order of the day, with investors taking profits on a recent rally in healthcare stocks, while consumer spending housing market concerns continued to weigh on discretionary retail (down 1.8 per cent) and property stocks (down 2.4 per cent).
The heavyweight financials sector inched 0.2 per cent higher but has dived more than eight per cent in two weeks after major banks reported home loan applications have plummeted since May's federal budget.
Resources advanced have gained 5.5 per cent since Monday, while gold stocks surged for a third straight week, further bolstered as US debt concerns that downgraded the greenback's safe-haven status.
The energy sector has advanced for seven of the past eight weeks, tracking with a resurgent oil price after the US threatened to broaden sanctions on Iran and its trading partners.
Local earnings season is in full swing, helping TPG Telecom, Guzman y Gomez, and Regis Resources shares rise on the backs of solid results.
On the flip side, Charter Hall, Perpetual, GQG, ARN Media and Inghams tumbled after their financials failed to impress.
The Australian dollar is buying 71.46 US cents, up from 71.22 US cents on Thursday.
Cryptocurrency bitcoin has had its best week in almost a year, surging almost 20 per cent to $US75,400 ($A105,550) after US President Donald Trump called on Congress to pass a crypto regulation bill.
ON THE ASX:
* The S&P/ASX200 fell 24.9 points, or 0.27 per cent, to 9,058.9
* The broader All Ordinaries lost 28.8 points, or 0.31 per cent, to 9,269.7
One Australian dollar trades for:
* 71.46 US cents, from 71.22 US cents at 5pm AEST on Thursday
* 113.56 Japanese yen, from 112.78 Japanese yen
* 61.09 euro cents, from 60.94 euro cents
* 52.35 British pence, from 52.30 pence
* 119.68 NZ cents, from 119.61 NZ cents
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