Market Participant Identifier (MPID)

A Market Participant Identifier (MPID) is a unique code assigned to each registered participant in a financial market — including stockbrokers, clearing members, trading members, and institutional investors — by the relevant exchange or regulatory authority to identify and track their trading activity. MPIDs are used by exchanges and regulators to monitor trading patterns, enforce position limits, investigate potential market manipulation, and attribute transactions to specific market participants for surveillance and compliance purposes. In India, NSE and BSE assign unique member IDs and trading member codes to their registered broker-members — these serve a similar function to MPIDs in the Indian context. SEBI uses these identifiers in its market surveillance systems to detect patterns of circular trading, front-running, insider trading, and coordinated manipulation by connected entities. For institutional investors including FPIs, each registered entity is assigned a unique FPI registration number that tracks their aggregate market activity. The concept of MPID is particularly important in fragmented markets and in regulatory frameworks that mandate pre-trade and post-trade transparency — ensuring that all significant market participants can be identified, monitored, and held accountable for their trading behaviour.