"Any successful investor/ trader has a " stop loss " mechanism in the trading plan."
Not true Henrietta. The greatest investor of them all - Warren Buffet - doesn't us stop losses. Enough said:
"After buying a farm, would a rational owner … start selling off pieces of it whenever a neighboring property was sold at a lower price? Or would you sell your house to whatever bidder was available at 9:31 on some morning merely because at 9:30 a similar house sold for less than it would have brought on the previous day?"