Nifty future gaps!

#1
As we know that when market is closed there is a window that alow us to put buy/sell orders(after hours). Now we can only put buy/sell orders in cash market. So when we can not put buy/sell orders in futures market then why nifty future opens with a gap up as was on 14th july when overnight us indices closed up 2% and asian idices were also up.
What I read in the books that there are floor members who earn spread or slippages, when they see that overnight buy orders are more than sell orders they open the market higher, buy doing so the pros who are waiting to sell at higher prices in the opening put sell orders and all buy orders get filled.
But know the question comes to my mind, when you can not put futures orders in after market then why nifty july futures opened on 4024 (14thjuly as closed on 3973 on 13thjuly).
 
#2
market sentiments ,my friend.
Future follows the price of equity market (either at a premium or discount), so you will always see gap up or gap down or flat depending on the current market sentiments.
You cannot put buy or sell orders in futures after market hours because unlike equity market future market is realtime transactions.