MiFID II Best Execution Monitoring: The Controls That Actually Get Tested

Best Execution: A Requirement With Specific Evidential Obligations

MiFID II's best execution requirement - set out in Article 27 of the Directive and the associated Commission Delegated Regulation (EU) 2017/565 - requires investment firms to take all sufficient steps to obtain the best possible result for their clients when executing orders. The regulation specifies the execution factors that must be considered (price, costs, speed, likelihood of execution, size, nature of the order, and any other relevant consideration), the relative weight to be given to those factors for different client types, and the governance obligations around the Order Execution Policy.

What the regulation does not specify in granular detail is how firms must demonstrate compliance with the best execution obligation through ongoing monitoring. The monitoring methodology is instead addressed in ESMA guidance and, increasingly, through supervisory communications that clarify what national competent authorities and ESMA expect to see in examination.

ESMA's 2024 supervisory briefings identified best execution documentation as a repeat deficiency across EU investment firms - not because firms lacked Order Execution Policies, but because their monitoring of whether execution actually met the policy standards was inadequate. This article examines what adequate monitoring looks like and what examination teams are checking.

Order Execution Policy: The Starting Point That Is Not the Finish Line

Most investment firms subject to MiFID II have Order Execution Policies that describe their approach to best execution - the execution venues they use for different asset classes, the factors they weigh in venue selection, and the frequency with which the policy is reviewed. The policy is published and provided to clients on request. The compliance team reviews it annually. The board approves it.

What ESMA's supervisory findings have consistently identified is that the Order Execution Policy is a statement of intent, not a demonstration of compliance. The compliance question that examination teams focus on is not whether the policy exists and is current, but whether the firm can show that actual execution decisions are made in accordance with the policy, and that the firm monitors execution quality continuously against the policy standards.

The monitoring gap takes different forms in different firms. Some firms have a policy that specifies venue selection criteria but no systematic process for verifying that dealers are applying those criteria in practice. Some firms have execution quality monitoring that covers equities and fixed income but not derivatives or foreign exchange. Some firms have monitoring at the trade level but not at the pattern level - they can review individual trades but cannot identify systematic execution quality deterioration across a venue over time.

What Execution Quality Monitoring Actually Requires

Adequate execution quality monitoring under MiFID II involves three distinct analytical activities that many firms conflate or substitute one for another.

Transaction Cost Analysis (TCA): TCA measures the cost of execution by comparing the price achieved against relevant benchmarks (VWAP, arrival price, midpoint at order submission, or closing price depending on the strategy and asset class). TCA is a quantitative discipline that requires access to granular trade data, market data, and a methodology for calculating implementation shortfall or execution shortfall against the chosen benchmark. Firms that have TCA capabilities can show, for any given time period, whether their execution costs were consistent with the quality standards their policy represents.

Venue Monitoring: Separate from per-trade cost analysis, venue monitoring assesses the ongoing performance of each execution venue against the criteria in the Order Execution Policy. A venue that was achieving best execution when the policy was written may no longer be achieving it if its market share, latency, or fill rates have changed. Venue monitoring must be systematic and documented, and the results must feed back into venue selection decisions and, where material, into policy review.

Outlier Detection: Even firms with good average execution quality should monitor for individual trades where execution was significantly worse than expected. Outlier detection is particularly important for retail client orders and for asset classes where liquidity is variable. Trades that fall outside the expected execution quality range should be investigated and documented - not as automatic proof of a best execution failure, but as a quality control process that demonstrates the firm is actively monitoring for issues.

The Annual Best Execution Report: What Has Changed

MiFID II requires investment firms to summarize and publish annually the top five execution venues for each asset class and the information obtained about execution quality for each venue. The RTS 28 reporting requirements were amended by MiFID II Quick Fix in 2021 to reduce the scope of the annual report, but the underlying obligation to monitor and document execution venue quality remained.

Examination teams reviewing best execution compliance have been looking at the consistency between what the annual report describes and what the firm's internal monitoring data shows. A report that states the firm used venues X, Y, and Z for European equities and that execution quality was satisfactory across those venues should be supported by internal monitoring data that demonstrates that conclusion. Reports that appear to have been prepared without access to execution quality data, or that describe monitoring that is more systematic than the firm's actual monitoring infrastructure can support, generate examination questions about the integrity of the reporting process.

The Systematic Internaliser Question

Investment firms that meet the thresholds to be classified as Systematic Internalisers (SIs) under MiFID II have additional best execution obligations that apply to their SI activity. SI status creates obligations around quote publication, price improvement, and execution quality reporting that apply to the firm's proprietary trading activity as well as to the execution of client orders in SI capacity.

Firms that have become SIs during the period since MiFID II's implementation - through organic growth in their proprietary trading activity rather than through a deliberate decision to become an SI - sometimes discover their SI obligations through examination findings rather than through proactive compliance monitoring. As we explore in our article on why manual gap analysis breaks down at scale, threshold-based obligations that are triggered by business activity changes rather than by regulatory publications are particularly prone to gap analysis failure in programs that track regulatory obligations through periodic manual review rather than continuous monitoring.

Building a Best Execution Monitoring Program That Withstands Examination

A best execution monitoring program that meets ESMA's expectations needs to integrate TCA, venue monitoring, and outlier detection into a formal governance structure with defined frequencies, escalation triggers, and documentation outputs. The governance structure should specify: who performs each monitoring activity, at what frequency, using which data sources, and with what approval and reporting requirements.

The documentation outputs should include: monthly or quarterly TCA summaries by asset class, venue performance scorecards with defined thresholds, records of outlier investigations and conclusions, documentation of any venue selection changes triggered by monitoring results, and annual best execution reviews presented to senior management and the board. These documents are the evidence package that examination teams will request, and their existence, completeness, and consistency with the policy is what determines the examination outcome.

Compliance teams that try to reconstruct execution quality analysis after receiving an examination request - pulling trade data and running retrospective TCA for the examination period - are producing documentation that examiners recognize as retrospective. The absence of contemporaneous monitoring documentation, even if the retrospective analysis shows satisfactory execution quality, is itself an examination finding about the monitoring methodology.

Conclusion

MiFID II best execution compliance is not satisfied by a well-drafted Order Execution Policy and annual report publication. The compliance obligation extends to systematic, documented, ongoing monitoring of actual execution quality against the policy standards. Firms that have policies but not monitoring programs are not compliant - and ESMA's supervisory findings have made this expectation explicit in ways that should inform every EU investment firm's compliance program assessment.

Building the monitoring program is an analytical and governance investment that requires cooperation between compliance, trading, and technology functions. The firms that make that investment consistently are the ones that treat best execution as a substantive conduct obligation rather than a documentation exercise.