Everything I've read on MatchNow (aka TriAct) is that there is no "advertising" of their intentions....so when you see the bid/ask it doesn't include anything that is happening on that exchange or platform.  As for knowing whether they're a buyer or seller....they are neither, its an ATS or alternative trading system. Buyers and sellers can use MatchNow instead of the TSX or another platform....both the buyer and seller are opting to trade over that ATS.