Does anyone have historical data. I recall reading that the COTs were bullish all the way from Naz 3500 or so until 2400 or so. I do not recall seeing numbers for the S&P.
If my recollection is correct, they can be wrong for long periods of time.
My take is that they have switched over to the EMINIs for increased flexibility. Getting in and out of the big contract is a lot harder to the best of my knowlege.