A word of warning, there are times when price spreads diverge for long periods, and you need experience to know when it is happening.
A recent example is the spread between brent crude and WTIC.
For decades the spread was quite predictable, but when brent began averaging more than $6 above WTIC, it was clear that the dynamic in the oil markets had changed.
I exited this spread with a small loss, there are ways to manage this, and this is a good example of when it doesn't work out, but most of them do work out well.
Good luck with your research into this interesting field
