if you want to stop loss.
the first thing is: stop trading no matter you have a position or not, just stop.
if the position is red and no margin involved, hold and wait, maybe days,or weeks, or even months, even years. when it becomes green,lock it. use option to lock or trail stop(stop does not work overnight, so should not apply, just simply end your trade profitablely)
if margin involved, dump the positin immedaitely stop trading. margins are killers. my IRA generate more profits than my margin account with less trading activities . those losers in 2009/2008, all become winners in my IRA,ride it out!
forget about technical anysysis, fundemental anaylsis,... the market has no logic most time. so you do not need think or overanalysis, let it be. the market often overreacts because of herd mentility, that is why bottom/top is hard to predict.
do nothing is the best deadly weapon toward consistent profit, and stop your loss streak immediately
happy trading