buyers depth miscman, I agree, if the 500's wanted stock they would put them on the top bid or pull them until the trading reached their price.
I don't expect them to take the offer all the time (or give the bid, if they're going the other way), but I am sceptic of large out of market bids.
To the 500k out of mkt bidders, pull them or put them where they can be hit, pussies!