Understanding Spreads, Commissions, and Execution Costs
The true cost of trading is often larger than the number a broker advertises. To compare brokers fairly, it helps to understand each component of cost and how they add up over time. This guide keeps the explanations practical and neutral.
The spread
The spread is the difference between the buy (ask) and sell (bid) price of an instrument. It is usually the most visible trading cost.
- Fixed spreads stay the same regardless of market conditions
- Variable (floating) spreads widen and narrow with liquidity and volatility
A tighter spread lowers your cost per trade, but spreads should be assessed alongside commissions, not in isolation.
Commissions
Some account types advertise very low or "raw" spreads but charge a separate commission per trade. In these models, your total cost is spread plus commission. A raw-spread-plus-commission account and a wider-spread commission-free account can end up costing a similar amount, so always calculate the combined figure.
Swaps and overnight financing
If you hold a leveraged position overnight, you may pay or receive a swap (also called a rollover or financing charge). For traders who hold positions for days or weeks, swaps can become a meaningful part of total cost and are worth checking before you trade.
Execution quality
Cost is not only about advertised prices - it is also about the price you actually get when your order fills. Relevant factors include:
- Slippage - the difference between the expected and executed price
- Requotes - being asked to accept a new price before an order executes
- Fill speed - how quickly orders are processed during fast markets
Under the EU's MiFID II framework, investment firms are required to take sufficient steps to obtain the best possible result for clients when executing orders (the "best execution" obligation) and to disclose costs and charges to clients. Even where you trade outside the EU, these principles are a useful benchmark for what good practice looks like.
Putting it together
To compare two brokers on a like-for-like basis:
- Add spread and commission for the instruments you actually trade
- Factor in swaps if you hold positions overnight
- Consider execution quality, not just the headline spread
- Read the broker's own costs-and-charges disclosure
A broker that presents its full cost structure clearly is easier to evaluate - and transparency itself is a positive signal. Verotify factors trading conditions and cost transparency into its broker scoring so these details are easier to compare side by side.