Investors are apparently even wondering whether losses this week signal the start of a rout.
"There’s a number of reasons why investors are feeling a little down in the dumps at the moment," says analyst Craig Erlam. "Corporate-earnings season has been mixed from an investor standpoint, and disappointing from an economic one."
EU Stoxx 50 -0.75%, London -0.2%, Paris -0.5%, Frankfurt -0.1%, Madrid -2%, Milan -1.1%.
U.S. stock futures: Dow -0.4%. S&P -0.4%. Nasdaq -0.4%