Quote from Equalizer:
Charles,
far be it for me to be the party pooper, but I believe a little more care is necessary here.
In particular I am intrigued by your calculation of "fair value".
This will be more problematic for say the ER2/NQ pair.
Plot data for a couple of years - for ER2/NQ pair, and take a look at the ratio.
Not a stationary process is it? Forget about the variance, even the mean is nowhere near constant.
Using your method all might appear to be going well, until your "fair value" is now far from fair. If you are going to investigate this approach, you might wish to detrend the ratio. I am not saying this will work and make you cubic cash either.
Just something to ponder upon before plonking real cash.
You might also find co-integration useful (be careful with correlation). Though you will pretty much always find that SIF time series (in the same market - i.e. US) are highly co-integrated and correlated.
Thanks for the advice.
Don't worry, I'm not trading this anytime soon. Just something that I'm playing with and researching. Still have a lot to learn.
Charles