Concerns over tensions in the Strait of Hormuz pushed oil prices closer to $100 a barrel on Wednesday, contributing to a decline in the Australian sharemarket to its lowest level in six weeks. The benchmark ASX 200 index fell 9.4 points, or 0.11 percent, closing at 8911.40, its weakest finish since July 27. The broader All Ordinaries index dropped 11.4 points, or 0.13 percent, to 9102.90. Meanwhile, the Australian dollar rose 0.15 percent, ending the day at 72.29 US cents.

The market saw mixed sector performance, with seven of the 11 sectors retreating. Gains in the energy and materials sectors were offset by losses in banking stocks. The materials sector was buoyed by a rally in copper prices, which reached a record high of $14,635 per metric ton on the London Metals Exchange. This surge supported gains in copper producers, with Sandfire Resources shares rising 2.00 percent to $22.95 and Capstone Copper climbing 5.47 percent to $16.00. Major diversified miners also recorded gains, as BHP’s shares increased 3.25 percent to $64.58 and Rio Tinto rose 1.89 percent to $179.33.

Energy stocks were boosted by the rising oil price amid escalating geopolitical risks. Woodside Energy shares gained 2.60 percent to $33.14, Santos closed 1.31 percent higher at $8.52, and Ampol added 1.37 percent to finish at $41.46.

However, the positive momentum in energy and materials was undermined by declines in the financial sector. Commonwealth Bank shares fell 2.17 percent to $155.25, National Australia Bank dropped 1.54 percent to $38.27, Westpac slipped 0.55 percent to $34.39, and ANZ shed 0.41 percent to close at $36.79.

The overall market response reflects investor caution amid ongoing uncertainty regarding tensions in the Hormuz Strait, a critical chokepoint for global oil shipments, which has contributed to upward pressure on crude prices and weighed on broader market sentiment.