its really an inexact science for me. i like to see at least 10%...after that, i see where it stands in relation to the chart and if the risk(losing what ive made) is worth the reward (further gains). when it comes to these things, a run is usually worth 30% or more so i like to take profits early. most peeps prefer instant gratification, you know like the 100%+ trade. i just like accumulating all of my 10,20 and 30% winners! try it out!