Most of my strategies work well on not all but most instruments, for example if I test a basket of stocks, it works on 80% of them, thus if the strategy is run against them all at once the entire result is profitable. Also I test across multiple timeframes, up markets, down markets. etc.
I agree with Sergio77. A strategy that works across multiple instruments - in the same Market or Sector, would show some promise. However, some markets are quite individual and a more "tailored" approach is necessary. In such a case there are other ways to ensure that curve-fitting is minimised.
I use the same core strategies with CL, ES, SPY, and a variety of actively traded stocks and ETFs. I've looked at a chart of NQ and the same strategies would work with that. I've also looked at ZN, same strategies work. My strategies are based on pure price action, so the only adjustments necessary are based on the volatility, which means my risk:reward ratios remain the same, but the size of the stop/target may change during periods of higher volatility.
Moreover, would you then devise and separate strategies based on particular sectors e.g. i have a strategy which performs really good on banking stocks and not so good on tech. Would this be simply curve fitting or is this the way we should devise strategies??
@dom994 Well, if you CAN use the same parameters across all sectors - I would! However, sectors are different and you may well lose a better model by NOT tailoring to the sector individually. BUT, it needs common sense, having same parameters by sector and ensuring that it works on more than just one stock within the sector would seem prudent.