ya all worry about curve fitting and returns, testing your insecurity, what,s the point, get out there and invest for the long term, the biggest curve you have to overcome is your way own thinking about investment, the market is proven over the long term, a simple chart provides the facts,
The point in being concerned/thoughtful about over-fitting is precisely that I’m not buying the market and holding, but looking to trade the account more aggressively based on a model, which hopefully is not over-fit.