How you guys can predict, or think you can predict, the next day's open from the closing price seems absurd to me. Each new day is an independent variable from the previous one. -- more or less, Prediction, anyways, is a fool's game. You might as well just go to Vegas to have more fun doing, or gambling, it. True trading is being able to do it in real-time. In the eye of the storm, or riding a nice...monsterous wave to profits, w/o getting wiped out, ..,, If you buy or sell at the closing, expecting an opening variable price...then you're leaving yourself heavily exposed to the great unknown, mysterious variable of time. Options and futures or just the stock are each their own unique games. -- that requires their unique set of variables and pros/cons to consider and judge and play, What you think are controlled elements from semi-predictable backtesting...are nothing more than varying degrees of semi-similar looking coincidences. Your Mind is not Free, but locked...within the matrix.
But Lawrence, isn't there likely SOME correlation between some items relating to the closing price and the next days open? Such as how did the market do in the last hour of trading - if it went up strongly its [more] or [less] likely to open up the next day? Maybe the correlations are not particularly high, but I bet some could find some correlations with back testing.
I say that because that's what happens, follow these index futures for a decade, you start to pick things up. patterns that occur over and over. Does it happen every night, nope, but it happens 70% of the time.
They just float higher, with very little resistance, happens over and over. Buy the close go to sleep wake up count your free money.