I have a question for those traders that are currently using openbook. I have found it useful so far but I am still trying to figure out how to best use it. Anyway the question I have is that sometimes I see the specialist in certain stocks put some size on the bid or offer (sometimes large, sometimes not very much) but that size does not show up in the book all the time. I had assumed if he posted a bid or offer that it would have to be on his book thus showing up in openbook. Does that mean he is flashing BS size or is there another reason why it does not show up in the book? I am guessing if he puts it there if you are fast you can NX him before he cancels his size. If anyone else would like to discuss openbook and has some good ideas on how to use it and want to exchange observations feel free to post here. You can also PM me if you feel you are giving a secret away posting it in the forum.