I have used this wonderful tool incorporated elsewhere and it is very useful. It is called ADR (Don't know what it stands for ) . It is a number that represents the gap in % between the high and low of the day for each particular stock. The ADR is a 14 day average of those daily variations for each individual stocks. Once you have the results you can look at the chart of the stocks and try to identify if their is one that has some sort of a pattern that reproduces itself daily. If so,you can start buying at point of reversal knowing that your potential daily gain could be close to your ADR.

I was only able to find a french video from the people offering this tool:http://www.youtube.com/watch?v=BOT6egHVkdM