'Knowing' what the S&P will do implies 100% certainty of a future event - not possible. Not least because other events that are not known or so readily predicted will potentially interfere.
In any case, a donation of the range and direction for one day in the trading calendar isn't going to get anyone far financially, you have to have a repeatable strategy.
Better to anticipate the potential direction and decide on a technique that will get you into that move at a sensible place with regards risk:reward, but also which generates its own inherent stop-loss so that if the move fails, at least you will capture profits or limit losses. At the same time, anticipate an entry point in the opposite direction so that if the market behaves unexpectedly you still have the opportunity of a trade in the reverese direction. Money management, risk:reward and stop loss rules still apply.
If none of this makes sense, this is likely ignorance not stupidity. Accept your ignorance as a signpost towards learning, avoid trading until you have absorbed the basics and can repeat your analysis 200+ times per year.
