Is under 10% Loss good to say to put stop loss at?
I think you should not put stop loss on the basis of percentage. It should be some support analysis that point if market reaches @ X price of this share then its other support much below it. So logically your stop loss should be just below the first support/resistance level of the diving market.
You need to be updated about your investment and do not wait for stop loss if your analysis is pointing that underlying fundamentals on that share are week, sell at once then.
I recommend avoiding stop-loss for several reasons, but primarily because if you are trading you should be paying attention. Using a stop-loss is like driving a Tesla with your eyes closed using Autopilot -- most of the time it is ok, but eventually you will die.
+1 , Quite interesting analogy.