I trade mostly equities and have been working continually on building and adapting systems and rules to trade by to remove as much emotion as possible (or all). Anyway, I've worked on a number of systems/strategies that obviously do better in some periods rather than in others. It got me thinking about whether there were ways to incorporate the market into the system, too. For instance, adding a factor that says only enter these long trades if the individual stock characteristics are met AND the market looks "oversold" in the short term or something similar. Anyway, was wondernig whether people that had built their own systems to trade individual stocks short term (1 day to 3 days) and were getting good results typically kept the systems focused internally on the individual stock or whether they tended to incorporate other elements, like the market action? Appreciate any feedback.