We define "THRUST" for a trading period as the difference between the lowest price and the highest price transacted during that period. The active S&P 500 futures contract is our measure of price of the whole American market.

        if the highest price of a period occurs earlier than the lowest price of the said period,  then Thrust Direction for that period is negative.

Four prices are of greatest interest within a given period:   the open, the close, the high, and the low.  We concern ourselves primarily with the last two, the high/low difference and DIRECTION, because this defines the greatest opportunity for making profit.  The direction from the first-occurring extremum to the second-occurring extremum is the "trend" for the period (positive/up or negative/down), and (with our help) is your "friend".  Maximum profit can be made any period by entering at the time of the first extremum, and exiting at the time of the second extremum, with a long trade if Thrust is up, or a short trade if Thrust is down.

By having the accurate prior knowledge of S&P Futures daily Thrust Direction,  which we can provide, you can determine that a price will occur before the Close, which will be higher than the Open if Thrust is positive (or lower than the Open if Thrust is negative).  Also, if Thrust is positive, then, near the start of a day, any buy below the Open price will be followed by an opportunity before the Close to sell above the Open price;  and likewise, if Thrust is negative, then, near the start of a day, any sell above the Open price will be followed by an  opportunity before the Close to buy below the Open price.  AS GOES S&P,  SO GO MOST STOCKS, INDEXES, AND DERIVATIVES!!