If it seems like markets in the US are increasingly tracking markets in Europe, it's because they have been. We went back to 1987 and calculated the 200-day rolling correlation between the one-day percentage moves of the S&P 500 and the EURO STOXX 50 index.
As shown below, the correlation between the US and Europe over the past 200 days is currently at its highest point ever at 0.78. Aside from a few brief periods, correlation between the US and Europe has been trending higher for 20 years now.
If you're looking for a data point showing one of the effects of globalization, you've got one here.