The article explores how financial crises affect stock market volatility in Australia, Singapore, the UK, and the US. Using data from 1992 to 2009, the researchers found that the Asian and global financial crises did not significantly impact stock returns in these markets. However, both crises did increase stock market volatility. The US stock market had the most significant influence on the volatility of smaller economies like Australia. Overall, there were significant volatility spillovers and co-volatility among all four markets, suggesting that diversifying investments across these countries may not reduce risk.