Execution Quality
A measure of how well a broker fills a trade relative to available market prices at time of execution.
What is Execution Quality?
Execution quality refers to how effectively a broker-dealer executes customer orders, measured by factors including price improvement (receiving a better price than the quoted NBBO), fill rate (what percentage of orders are fully executed), execution speed, and effective spread (the actual cost of transacting relative to the midpoint price). Under SEC Rule 605, market centers must publish monthly execution quality statistics, and Rule 606 requires broker-dealers to disclose order routing practices. Execution quality is central to evaluating the impact of payment for order flow (PFOF) arrangements, where brokers receive compensation for directing orders to specific venues — potentially creating conflicts with best execution obligations.
Example
Robinhood's 2020 SEC enforcement action highlighted execution quality concerns: while offering commission-free trading, its PFOF arrangements routed orders to market makers who provided inferior prices. The SEC calculated customers received approximately $34 million less in total execution quality compared to Robinhood's competitors over a 2.5-year period — demonstrating that zero-commission brokerages may impose hidden costs through execution shortfalls.
Source: SEC — In the Matter of Robinhood Financial LLC (Release No. 34-90694)