When the U.S. stock market opens in New York, the European markets have already been in session

Question:

When the U.S. stock market opens in New York, the European markets have already been in session for several hours. Does the activity in European markets have predictive content for the U.S. market? Download the British stock index (FTSE) and the SP500 index at the daily frequency. Examine whether FTSE returns can help to forecast SP500 returns.