🔗 Calculating P&L when a trade spans multiple sessions

The inaccurate weekly P&L digest led to the discovery that a genuine trade was missing from the records, while a non-existent one had been erroneously logged. This article, written by Ryan Born, delves into the unique intricacies of trade accounting when positions cross over multiple trading sessions, an issue often underestimated. A session doesn't align with calendar days; rather, it's defined by strategy configuration and optimization. The potential for trade splits occurs not just with overnight positions but also during simultaneous optimizations. The author details the consequences of these splits on trade metrics, highlighting how a phantom trade can distort the numbers and yield misleading P&L figures. The real challenge lies not in simply looking back one session, but in accurately determining the point where the account was flat and aligning trades with their respective sessions — a more complex but necessary solution.