"The worse case is that all trades , winners or losers,ARE RANDOM.If that's the case ,there is no difference between starting after a positive or negative streak [...] The big question is if the system will continue working.I've done tons of research on that and have not found anything that predicts if a system or approach will continue to make money" /R. Vince/ Agree, however: What if I`ve done tons of research as well and while there is no indication whether the system will continue to work, I`ve found in many cases that actually it is important whether you increase position after negative or positive streak. I know also by my own experience that many system traders start trading new strategies after losing series. Are they wrong ? Is this just psychology behind it or something else ?