Hi
Thanks for your reply. No, we cannot identify a specific amount in market volume is the short answer.
The following selection variables might be of help to you:
traded_{price}
most_traded_price
traded_last
most_traded_volume
all the above need the ladder open on the selection.
If you are wanting the unmatched back and lay volume you can use:
back_volume
lay_volume
and you can do your comparison every 0.05 seconds. The problem with this is you will need to do it in user variables for every selection and it will slow the trigger down a lot.