was recalling info for stock indices rather than individual stocks.

stock index futures are 23 hours: http://www.cmegroup.com/trading-hours.html#equityIndex

stock volume is larger than futures (347B global avg daily volume vs 280 in jan 2016, not sure about now), but futures larger than ETFs (280 vs 88)

youll have to convince me that institutional investors dont drive futures volume, cant find data offhand but wont give you benefit of the doubt on that one :)