BBO feed is a real-time data feed that provides Quotes (best bid/ask quotations) for all traded securities.This is a top of book feed that publishes updates for every event in real time.
The BBO Feed is available for:
Pillar Publisher Client Spec
XDP BBO Client Spec 2.5a
Pillar Refresh/Retransmission Common Client Spec
XDP Common Client Spec v2.3d
Updated Halt Condition Codes - 03/22/2021 - all markets