US has busy opening/close and lighter midday action. Eurex (DAX/ESTX) has somewhat busy opening and MUCH higher volume during main EU closings/overlap with US open. Rest of the session is anemic in terms of volume and follows US in terms of direction. All good and well? But why EUREX closing volume is much higher then opening volume, while US volume is symmetrical during open and close? Both markets overlap and avail themselves to participants from all timezones, but US stays symmetric while EUREX does not? Could it be that big EUREX market participants prefer to trade closer to US open and do not want to place bets during EU open? Or maybe US traders come into EUREX and trade, but EU traders prefer to take off and sip coffee instead of trading US markets and causing US open volume be significantly higher then US close? Not sure what is going on but would like to hear thoughts from people who care about volume patterns. Help me understand!!!