Changes in technology and regulation have resulted in an increasing number of trading venues in equity markets in Canada. New trading platforms have intensified price competition and have encouraged innovation, and they do not appear to have segmented trade. But the increasingly complex market...

We analyze trading dynamics as successive high-frequency trading (HFT) firms begin to trade stocks in an equity market. Entrants compete with incumbents for volume, and there is crowding out. Earlier entry is associated with larger effects. After Passive HFT entry, incumbent spreads tighten....