Pooled Equity Trade — Happy Path Message Flow

OMS → Market → Integration → Back Office → CREST   |   Full Settlement (T+2)

Pre-Trade Execution Post-Trade / Allocation Settlement
#
Portfolio
Manager
OMS
Broker /
Market
Integration
Layer
Back
Office
CREST

⚠ Integration Layer Connectivity Risk — Critical Window

Messages 08→10 must complete before the Back Office's CREST instruction deadline. The broker submits their CREST instruction immediately after execution (msg 11). If the Integration Layer loses connectivity and msg 08 is delayed, the Back Office never generates msg 10, the broker's instruction sits unmatched in CREST, and settlement fails. For T+1 securities the recovery window is measured in hours.