Sizing-up is an action of an aggressor dealer asking how much more volume can the quoting dealer do on top of the initial volume that was shown for the posted price.
a) When an aggressor dealer asks for a bigger volume for a posted price without specifying any amount, and the quoting dealer responds with a volume, the aggressor dealer MUST deal the full volume disclosed since the quoting dealer has revealed his risk position already, regardless of the counterparty credit line availability.
b) When the aggressor dealer asks for a specific amount and the quoting dealer responds with a volume more than the amount specified by the aggressor dealer, the aggressor dealer is only committed to deal up to the amount that he requested. If the quoting dealer responds with a volume less than what was requested by the aggressor dealer but greater than the original amount shown, the aggressor dealer is committed to deal the full new amount that was given by the quoting dealer.
c) When the aggressor dealer asks for the total volume from the quoting dealer for a posted price and the latter responds with a question, (i.e. he asks how much volume the aggressor is interested to do without mentioning any amount), and the aggressor dealer responds with a specific volume, the quoting dealer should deal the full amount given by the aggressor dealer. The rationale is the same as section 7.a.