Effective/Quoted Ratio
The Effective/Quoted Ratio compares the average effective spread with the quoted spread, or the difference between National Best Bid and Offer (NBBO) at time of order entry and a firm's trade execution.
When an order is executed exactly at the NBBO, the Effective/Quoted Ratio is 100%. In other words, a 100% Effective/Quoted Ratio indicates an order was executed at bid for a sell order or at offer for a buy order. A 0% Effective/Quoted Ratio indicates that the order received the midpoint between the bid and offer.
Simply put, lower is better.
Percentages lower than 100 indicate a better execution
National Best Bid and Offer
100%
National Best Bid and Offer
Source: S3, a third-party analytics provider. Figures include orders sized 100–1,999 of S&P 500 stocks only, for the 1st quarter ending March 31, 2024.