how does this work ? is there some hedge fund or prop firm that tries to keep the bids / offers matched in equal numbers in between trades overnight ? many times I will see 10 X 10 8 X 8 3 X 3 etc in the e mini sp500 contract its almost as if a program is out there to equal out the bids and offers or match them up of course after a trade or two go through if they do not match up the prices will go to the next level or two and the same process will occur again