I've read about this before on their website directly and via this ITG paper.
But I was wondering if there are any other good references I can supplement my understanding with? For example, I'm not sure I understand what the risk less arbitrage would be if the reference price were not in line with the near price near the end. Isn't this impossible based on their definition? Or just from the fact that the reference price is constrained to be within the BBO?
