Loose language here: in the US you choose which exchange you want to be your primary listing. Listed securities can and usually do trade on all exchanges. Excha

Loose language here: in the US you choose which exchange you want to be your primary listing. Listed securities can and usually do trade on all exchanges. Exchanges have different liquidity profiles and market makers. The rules are enforced to ensure that you can send an order to any exchange and you should always get the best price even if it's on another exchange. During regular market hours...