There is a lot to know and understand about the behaviour of a market at the Open and at the Close. This is topic of rich interest, undoubtedly. It is intriguing when it is said 'Amateurs play the Open; professionals play the Close.' Presumably amateur means individual traders, prop or independent, and assorted others? Presumably professional means the funds and institutions? By Open I mean the first hour and half and by Close, I mean the last hour and half of the market. Take the Dow, most often the day high or day low can be captured in the first hour and half .. not always just mostly. Perhaps I should give an example with my own focus. I have my own system for scooping out the difference between the hi/lo or lo/hi pattern of the day. So my focus is on the Open period and I just use the rest of the market day to work out my system each day. I only need or want to day trade so thats what I do; also my targeting is on the maximum each market day gives and in my case the instrument is the DOW. Is it true therefore that 'Amateurs play the Open; professionals play the Close.'? Do you prefer the Open to the Close or vice versa?