The benchmark S&P/ASX200 (^AXJO) has closed down 0.71 per cent to 6,014.60 points, despite showing signs of improvement at midday.
The broader All Ordinaries index (^AORD) also closed down 0.61 per cent.
One Australian dollar was buying 69.7 US cents at 4.30 AEST.
What happened this morning?
The benchmark S&P/ASX200 (^AXJO) has opened 0.3 per cent lower at 10.39 AEST to 6,039 points, after global markets finished weaker on growing global coronavirus concerns.
The broader All Ordinaries index (^AORD) also fell 0.23 per cent to 6,149 points.
Aussie investors will be following the negative lead of European markets today, after Wall Street closed for the Independence Day long weekend.
Locally, virus concerns are increasing too: nine housing commission blocks in Melbourne remain in lockdown, as infection rates continue to soar in Victoria.
Health shares were lower by 0.73 per cent and industrials were down 0.66 per cent, but energy sectors were up 0.39 per cent.
The big four banks had mixed results, with ANZ and NAB edging higher while CBA and Westpac slipped.
One Australian dollar was buying 69.54 US cents at 10.07 AEST, up from 69.46 US cents at close of trade on Friday.
What happened over the weekend?
US stocks had Friday and Monday off, with investors taking a long weekend to observe the Fourth of July holiday weekend.
The holiday weekend comes as the US continues to record 50,000 daily virus cases.
Over in Europe, the Stoxx Europe 600 closed down 0.8 per cent, and the UK FTSE finished 1.3 per cent lower as investors became less optimistic about a speedy coronavirus recovery.
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