This is definitely not the reason. If you look at the COT statistics above you will see that commercial hedgers
-> have a net short position of 16,865 contracts of the big S&P 500 futures
-> have a net long position of 264,522 contracts of E-mini S&P 500 futures
If you convert the 16,865 contracts to E-mini equivalents, you will get 84,325 contracts short.
So it seems that the same group is long the E-mini while it is short the big S&P 500.
Don't believe in any Statistics that you have not forged yourself!
The contradiction can be explained in two ways.
(1) The stastistics above looks at the difference between long and short positions and shows net positions per group. If you look at the ratio between long and short positions of comnmercial hedgers you would find
Big S&P 500: long 203,685 - short 220,500 -> ratio long/(long + short) = 48%
E-mini S&P 500: long 2,369,188 - short 2,104,666 -> ratio long/(long + short) = 53%
This means that out of 100 positions in the big S&P 500 futures held by commercial hedgers there are 48% long and 52% short positions. Out of 100 positions in the E-mini S&P 500 futures there are 53% long and 47% short positions.
In the end this is not a big difference. It is just the way that chart presents the difference. I suggest that you also look at COT ratios and not only at absolute figures.
(2) As I said in my prior post, the aggregation of positions into non-commercial and commercial positions does not make sense. Swap dealers and index traders are included with commercial positions, although they may be both sell side dealers for commercial (hedging) customers and enter speculative positions on their own account.
For more details also see pages 44 - 51 of the paper below:
i said maybe for starters,and your example ,was 11.5 /1 on the long side ....and 9.5 to 1 on the short side,since you watch it,i dont have access to these numbers,it would be interesting to track the ratio and see if there is a divergence and if it gives any pre move clues,obviously the one example can not be used as an avg to measure against...like i said, maybe, it was only a guess