Not that hard really.
Say, as every stock does AAPL reports earnings after the bell (don't know when they will or if they have already) and they are better than expected. AAPL reprices in AF trading.
So since futures are based off of stock price expectations in the future if the markets believes, even if is it turns out to be erroneous in retrospect, AAPL and other stocks cumulatively should be higher then higher they will go.
Look into fair value/arbitrage/program trading/etc.
Yes but how do you know it is AAPL that should move up and not (say) TSLA that moved the index in the absence of market moving news.

