澳大利亚S&P/ASX200指数7月31日（周四）开盘下跌45.10点，跌幅0.52%，报8711.30点。

Core Points - The S&P/ASX200 index in Australia opened on July 31 with a decline of 45.10 points, representing a decrease of 0.52%, closing at 8711.30 points [1] Summary by Category Market Performance - The S&P/ASX200 index experienced a drop of 45.10 points, indicating a negative market trend for the day [1] - The index's closing value was reported at 8711.30 points, reflecting the overall market sentiment [1]