As a trader we perform a technical analysis based off "historical data" where was the money, how did the money progress to where it is TODAY". Our job as traders is to what? PREDICT FUTURE price action. If my job is to see where price is going (the profits are unlimited) so, the only thing we need to know is where to stop the money and your stop loss is not only based off of your personal financial criteria but also where price dropped LAST ( PAST ) IN BACK OF US. MAKE the future based off of historical facts.