Trading in the U.S. index futures suggests that Wall Street’s sell-off is far from being over as the Brexit risk has worsened the global economic outlook. Most Asian markets closed lower for the session, although some of the markets in the region were closed for Ramadan holiday. European stocks are also notably lower amid worries concerning the repercussions of the Brexit, when it eventually happens, and weak German factory orders data. Commodities have turned mostly lower and risk currencies are also weaker. The domestic markets may also track a couple of Fed speeches and a service sector activity data due shortly after the markets open.