1) Yes, but as I've said elsewhere there is a lot of information in the world other than the last hour's orders (why do people always forget this?) 2A) Prevent

1) Yes, but as I've said elsewhere there is a lot of information in the world other than the last hour's orders (why do people always forget this?) 2A) Preventing unmatched bids/asks will not work. Remember that you are starting at zero. All bids/asks are unmatched when you start with an empty order book. If you relax this some then yes you will leak and you are back to where you started. 2B) If you handle things sequentially then you have reintroduced a speed imperative. I, again, have an incentive to go fast to get first in line. 3) Yes, of course you are taking it away from everyone, but that matters more to me (an unsophisticated guy with no real time market research) than it does to BIG_HEDGE_FUND_GUY who does have such things and can, more easily, figure out what the market price should be without the help of the market. You are putting me at a disadvantage and him at an advantage. Is that really your goal?