Because we all know how meaningless the numbers can be when posted on Level II. Normally they use a 10K number on a larger lot when it is "all or nothing", and the 10K doesn't clear until that larger lot is covered. Maybe for some reason a trader had an odd lot of 81,427 that they wanted to sell "AON", and it hasn't cleared yet! Who knows, with all of the games being played by the MM's! Just life here in pennyland!