National Market System - NMS

For most of us, stock trading happens as a series of clicks. It’s basically online shopping, just for corporate shares instead of microbiotic tube socks or protein shake powder. But the series of connections that spring into action after we make those clicks are relatively complicated.

That background processing takes place on the National Market System. It represents the equity trading system in the U.S., connecting traders with major exchanges. The system includes processes for clearing, quote distribution, trading, and depository operations.

See: Electronic Communication Network (ECN).