A-Book vs B-Book: infrastructure follows the risk model.
A-Book, B-Book and hybrid models create different technology requirements. Routing, liquidity connectivity, exposure monitoring, data quality and operational controls should be designed around the chosen risk workflow.
A-Book requirements
External routing places more emphasis on bridge or gateway connectivity, liquidity relationships, failover, execution monitoring and network quality.
B-Book requirements
Internalization increases the importance of risk visibility, pricing integrity, dealing workflows, exposure controls and operational monitoring.
Hybrid architecture
Hybrid brokers need clear routing rules, consistent market data, observability and change-control processes so risk logic remains auditable and operationally manageable.