On Monday, the Australian S&P/ASX 200 index experienced a 0.4% decline, closing at 8,926 points, its most significant drop since April 2. This downturn was triggered by the collapse of U.S.-Iran peace talks and the announcement of U.S. sanctions blocking maritime traffic to and from Iranian ports. The previous week's optimism, fueled by a 4.4% rise in the index following talks in Islamabad, evaporated as negotiations ended without an agreement. The renewed tensions have raised concerns over oil supply, pushing Brent crude prices back above $100 per barrel. This situation has created a stagflationary environment, negatively affecting equity prices, according to Kyle Rodda, a senior financial market analyst at Capital.com. The mining sector fell 0.4%, primarily due to a 2.1% drop in gold stocks, while energy stocks gained 2.1% as crude prices rose. In New Zealand, the S&P/NZX 50 index fell 1.2% due to a 12.4% decline in a2 Milk shares, which cut its profit guidance amid supply chain issues.