Transaction Reporting: The Foundation of Effective Market Abuse Oversight

High-quality MiFID II transaction reporting is a critical regulatory control within a firm’s market abuse framework under the UK Market Abuse Regulation. It underpins the FCA’s ability to detect insider dealing and market manipulation and directly influences how a firm’s governance, systems and controls are assessed by supervisors and enforcement teams.

Inaccurate, incomplete or missing transaction reports materially increase the risk that market abuse goes undetected. Errors in trader identifiers, decision-maker fields, execution timestamps, trading capacity or instrument classification weaken the FCA’s ability to reconstruct trading behavior, identify suspicious patterns and link activity to individuals with access to inside information. From a regulatory perspective, poor data quality is not merely a technical reporting failure, it is a control failure that undermines market integrity.

Previous FCA enforcement action demonstrates that transaction reporting failures are increasingly viewed through market abuse lens. The regulator has explicitly linked inaccurate or missing reports to an increased risk that insider dealing and market manipulation could have occurred without detection. As a result, firms with weak reporting controls face heightened exposure not only to breach of MiFIR transaction reporting obligations, but also to broader conduct, governance and SMCR accountability risks.

As the MiFIR transaction reporting regime is streamlined through reform, supervisory tolerance for poor data quality is expected to reduce rather than increase. Fewer fields and a narrower scope mean clearer expectations, sharper accountability and less scope to attribute errors to regulatory complexity. During transition periods, when systems and reporting logic are changing, the risk of control breakdowns is particularly acute and directly elevates market abuse risk.

For senior management, the implication is clear. The quality of transaction reporting is inseparable from the firm’s ability to demonstrate effective prevention, detection and escalation of market abuse. Independent assurance over reporting accuracy and completeness should be viewed as a core component of the market abuse control framework and a key safeguard against regulatory intervention and enforcement action.