Druckenmiller on why most investors can't sell losers:
"if the reason i bought a stock is no longer the case, i don't care what i paid for it."
"if i bought it at 60 and it's 50 because the market discovered the problem before me, i have no emotion whatsoever."
"after a while you develop enough confidence that you're not afraid to clean the slate and start over. because you have the confidence that you'll be successful again."
"you're not going to sit there in a lazy position that you're not that sure about anymore. just clean house."
"i don't care what i paid for a stock. it's absolutely irrelevant to my investment process going forward."
then on buying back higher than he sold:
"i don't like it. but i'm perfectly willing to buy something back higher than i sold it. some people can't get themselves to do it. i can."
this is the exact same principle behind properly managing strategies. if the edge isn't there anymore, turn it off. don't sit in it hoping it recovers just because you spent three months building it. clean house. start fresh. the next opportunity doesn't care about your sunk costs.