What must participants provide upon TSO's request regarding their positions?

Participants are required to provide evidence of a single position of its customer account upon the request of TSO (Transaction Surveillance Office). This stipulation is crucial for regulatory compliance and for maintaining the integrity of the financial markets. By providing this evidence, participants enable the TSO to monitor and assess trading activities for unusual patterns or potential market abuse. It ensures transparency and allows regulators to have a clear understanding of participants' positions at any given time, which is essential for effective oversight.

While other options may represent valid considerations in trading and compliance contexts, the specific requirement to substantiate a single position directly addresses the TSO's need for detailed information regarding market positions, thereby facilitating monitoring and risk management. This helps to protect market integrity and safeguard against potential malpractice.