On May 11, 2023, Australian shares experienced a 1% decline, with the S&P/ASX 200 index settling at 8,661.4 points. The downturn was primarily driven by heightened risk aversion following U.S. President Donald Trump's rejection of Iran's peace proposal, which has intensified geopolitical tensions. This situation has led to a renewed interest in safe-haven assets and negatively impacted equities. Notably, CSL, a prominent Australian biotech firm, saw its shares plummet over 20%, marking its worst trading day since mid-December 2016. The company announced a reduced earnings outlook for fiscal 2026 and flagged $5 billion in non-cash impairments over the next two years. This significant drop affected the health sub-index, which fell by more than 9%. Additionally, financial stocks decreased by 1.7%, with major banks losing between 0.6% and 2.6%. In contrast, energy stocks gained nearly 1%, benefiting from rising oil prices amid concerns over global supply disruptions due to the ongoing conflict in the Middle East.