12,300 total volume with 7,400 of that on TriAct.

Here's what TriAct's webpage says:

TriAct Canada Marketplace LP offers specialized marketplaces and order execution services for Registered Canadian Investment Dealers and their clients to trade Canadian listed equities. TriAct operates MATCH Now, Canada’s premier broker-neutral dark book.

MATCH Now is a non-quoting marketplace where order information is not visible to other traders. A proprietary algorithm automatically matches buy and sell orders. TriAct does not participate on an agency or proprietary basis in any trade.