Best Execution Policy

A best execution policy is the written document in which an investment firm or broker explains how it handles client orders to achieve the best possible result for the client. It sets out the execution factors the firm considers, such as price, costs, speed and likelihood of execution, how it ranks them for different clients and instruments, which venues and counterparties it relies on, and how it checks that the policy is working.

The policy is how a firm puts into practice its legal duty of best execution, a central conduct obligation for brokers and portfolio managers. In Europe the duty is set out in MiFID II; in the United States it arises from FINRA rules and broker-dealers' duties under securities law. The same principles apply across shares, bonds, derivatives and foreign exchange, with adjustments for how each market trades.

Someone who asks a friend to buy a used car for them expects the friend to shop around, not just take the first offer from a cousin's garage. A good price matters, but so do hidden fees, the condition of the car and how quickly the deal can be done. The friend should be able to explain why the chosen deal was the best available.

A best execution policy is a firm's promise to do that with clients' orders, written down in advance. It explains where the firm will send orders, what it will look for and how it will check that clients are actually getting good results, so the firm cannot quietly favour venues that pay it rather than ones that are best for the client.

Article 27 of MiFID II requires investment firms to take all sufficient steps to obtain the best possible result for clients when executing orders, taking into account price, costs, speed, likelihood of execution and settlement, size, nature and any other relevant consideration. For retail clients, the best result is judged mainly by total consideration: the price of the instrument plus all costs of execution. Firms must:

• Establish an order execution policy and obtain clients' consent to it.
• Obtain express consent before executing orders outside a trading venue, where that is permitted.
• Monitor the effectiveness of their arrangements and review the policy at least annually or after a material change.
• Be able to demonstrate to clients, on request, that orders were executed in line with the policy.
• Avoid receiving inducements for routing orders to a particular venue that would conflict with the duty.

Firms were once required to publish an annual report on their top five execution venues under a technical standard known as RTS 28, but that requirement was removed in the EU and the UK after it proved of little use to clients. The 2024 review of MiFIR also introduced an EU ban on receiving payment for order flow from retail client orders, with a transition period ending in 2026.

In the United States, FINRA Rule 5310 requires broker-dealers to use reasonable diligence to find the best market for a security and buy or sell in it so that the price to the customer is as favourable as possible under prevailing conditions. Firms carry out regular and rigorous reviews of execution quality across venues, including exchanges, alternative trading systems and wholesale market makers. SEC rules require market centres to publish execution quality statistics and brokers to disclose where they route orders and any payment for order flow they receive.

Firms build execution arrangements around the policy: smart order routers that compare quotes across venues, algorithms for working large orders, broker selection panels and rules for when to trade a block trade or a limit order rather than a market order. Monitoring commonly relies on transaction cost analysis, which compares executed prices with benchmarks such as the arrival price or volume-weighted average price and measures slippage and the bid-ask spread paid. Oversight committees review results, venue performance and any conflicts of interest, and the conclusions feed back into the policy, together with lessons from algorithmic trading controls and data from regulatory transaction reporting.

Best execution is a process obligation rather than a guarantee of the best price on each trade, and judging it is hard in markets where prices are not publicly quoted, such as many bonds and over-the-counter derivatives. Policies are often criticised as generic documents that say little about actual routing decisions. Conflicts remain a concern, especially where brokers receive payments or other benefits from the venues they use, or route orders to affiliated market makers.