I was told that the margin for holding spread in cpo will increase by 25%. But the outright margin for futures on cpo remained unchanged.

 

Maybe:

1 Most of the OI  is spread trading, and there are some (probably longs) under the kosh

2 The ones who long cpo futures outright, most probably are already sucker punched and cut loss

3 Most trade in 3rd month are probably day trade gambling