In short
- Brokers must take all sufficient steps to obtain the best possible result for clients.
- They must publish an order execution policy.
- Fair handling of slippage is a good test.
The execution factors
When executing your order, a broker must consider:
- Price
- Costs
- Speed
- Likelihood of execution and settlement
- Size and nature of the order
- Any other relevant consideration
For retail clients, total consideration — price plus costs — is usually the most important.
What an execution policy should tell you
- Whether the firm acts as principal (your counterparty)
- How its prices are derived from the underlying market
- How market, limit and stop orders are filled
- How slippage is applied — ideally symmetrically, both for and against you
- What happens during gaps, outages and extreme volatility
How to test it yourself
- Compare the broker's quotes against another source at the same moment.
- Record fills on market orders during quiet and busy periods.
- Note whether you ever receive positive slippage.
- Check how stop orders are filled around news.
Concerned about a fill? Keep the ticket number and timestamp and raise it with the broker — see how to complain.
Frequently asked questions
Does best execution mean the best price every time?
No. It means taking all sufficient steps to obtain the best possible result, considering price, costs, speed, likelihood of execution and other factors — consistently, across orders.
Where can I find a broker's execution policy?
In the legal or documents section of its website. Brokers must provide it to clients.
CFDs and spread bets are complex instruments and come with a high risk of losing money rapidly due to leverage. Most retail investor accounts lose money when trading these products. You should consider whether you understand how they work and whether you can afford to take the high risk of losing your money.