I see ARCX flashing size on and off on all the nasdaq stocks I trade. Both on the bid and the ask, always the best bid/ask. It seems like ARCX is the major player in almost every stock now. What is the deal with ARCX, are they the hedge funds favorite ECN now, and why the flashy thing?
ARCA is an extremely liquid ECN . Depending on what stocks your trading it could be traders trading for liquidity rebates.