Considering randomness into an equation, I see prices move incrementally 5%, +2.5%, +1.25%, consolidate, pullback or move ahead in the same direction. I am not typing all the research I've done and used but wanted to know if there are any mathematicians/traders who understand what I am talking about. The general targets help emotionally and sometimes show a range of 20 to 80 cents off the target. Depending on the time fame of a chart (or a high/low to start from), high volatility stocks might start at 10% while ETFs like SPY or DIA might start at 2.5% (+1.25%, etc.) The reason I starting thinking about this was because a FX mentor told his student (a friend), to take 5% profit and exit a trade. Why 5%? Obviously there was profit and I started to look at a lot of price movements over time. Feedback from mathematical professionals is appreciated.