they cant , they are too large,so they massage the prices and take pieces off and add, both directions, rare occassions that they dump or add in size, not that rare but only a a few times a month and not on a monthly basisInteresting, you reckon this is how the big players manage their trades. So they will be gradually dumping all those contracts and then loading up again when they are done. Makes sense I suppose if you have a large amount of contract to load\unload and don't want to dump them all at once.