can someone explain opening price signal? i read a book and it doesn't seem to make sense to me from their explanation.
You may want to list the title of the book you are referring to. Also, you may want to elaborate on the context of its usage. Opening price signal would have various meanings from trader to trader.
The Opening Price Signal is an approach developed by Lukeman himself to determine intra-day trends. It compares the difference between the last executed trade and the opening price, and if that difference is equal or greater to 1/4 points, then this is a positive trend, and if equal or less than -1/4 then the trend is negative. You should always trade in the direction of the OPS trend. Also when the OPS changes from negative to positive or vice versa, then this is a signal of a change in mood. OPS = Last Price - Opening Price
There is an excellent book by Larry Pesavento called "The Opening Price Principle." Quite simply stated, the opening price will be very near (within 20%) of either the high or low for the day about 70% of the time. If you look at the SPM02 the last few weeks, he is right on.