Preferred embodiments of the subject invention comprise the steps of: (a) electronically receiving first participant information, said first participant information including a first order having a first price and a first size; (b) electronically receiving a second order having a second price and a second size from a second participant; (c) executing said second order against said first order if said first price matches said second price and said first size matches said second size, and if said first participant information indicates that said first order is exposed to immediate matching against incoming orders; and (d) executing randomly-timed match check events wherein other orders are matched against the first order if said first price and said first size match prices and sizes of said other orders and if said first participant information indicates that said first order is to be exposed to randomly-timed match check events.