The paper reviews the correlation between the S&P 500 and the FTSE 100 before and during the 2008 global financial crisis. It found that The S&P 500 has a strong causation effect on the FTSE 100, both before and since the financial crisis. This link seems to have increased after the October 2007 peak in the S&P 500. Since the crisis, the FTSE 100 appears to have a weak causation effect on the S&P 500. Before the crisis there was no apparent impact on the S&P 500’s movements from movements in the FTSE 100
