Forex Spread Explained: Costs, Examples and Scalping Impact
Reviewed . All prices and account comparisons below are hypothetical examples, not live quotes or tested trading results.
The forex spread is normally a cost to the retail trader taking the broker's quoted prices. You buy at the ask and sell at the bid; the difference creates a hurdle the market must overcome before that trade is profitable. A wider spread does not hand you a larger profit simply because the gap between the two prices has increased.
Understanding this helps with broker comparisons and with deciding whether a short-term setup has enough room to work. A sensible-looking entry can become unattractive when its potential move is small compared with the spread, commission and execution costs.
Bid, ask and spread in one example
The bid is the price at which you can sell, and the ask is the price at which you can buy, as explained in OANDA's bid-and-ask guide. For EUR/USD, one conventional pip is 0.0001; an extra decimal place on the quote is a fraction of a pip. Many JPY pairs use a different pip convention, so check the instrument instead of assuming that every last digit is one pip.
| Item | Value | Meaning |
|---|---|---|
| Bid | 1.10000 | Price available to sell |
| Ask | 1.10012 | Price available to buy |
| Spread | 0.00012 | Ask minus bid, equal to 1.2 pips |
If you buy at 1.10012 and immediately close at an unchanged bid of 1.10000, the price difference is a loss of 1.2 pips. Assume a USD account and a 0.10 standard-lot position of 10,000 EUR. Each pip is then $1, making the loss $1.20 before any separate commission or other charge.
How the spread affects the realised result
Now suppose the bid rises from 1.10000 to 1.10100 and you close the same buy there. The bid chart has moved up 10 pips, but your entry was the ask at 1.10012. Your price gain is therefore 8.8 pips, or $8.80 in this example, before separate charges.
The useful calculation is closing bid minus opening ask for a buy, or opening bid minus closing ask for a sell. When you calculate profit from those actual execution prices, the spread's effect is already included. Do not subtract another full spread from the same result. A backtest using only one price series needs an explicit cost assumption because it does not automatically contain both sides of the quote.
Spread is only one part of the cost
| Cost | What to check |
|---|---|
| Spread | The bid–ask difference on the instrument when you trade. It is reflected in execution prices. |
| Commission | Whether the quote is per side or for opening and closing combined, and whether it is per lot or another unit. |
| Overnight financing | Charges or credits for holding the position across the provider's financing time, including the schedule. |
| Slippage | The difference between a requested or expected price and the actual fill. It can improve or worsen execution. |
| Currency conversion and payment fees | Any relevant account-currency conversion or third-party funding/withdrawal charge. |
“Zero commission” does not mean zero trading cost. Equally, a commission account is not necessarily expensive overall: its narrower spread may offset the separate fee. Compare the same position and holding period, rather than comparing two different advertising headlines.
A lower spread can still produce a higher total cost
Here is a second illustration. Both accounts use the same USD-denominated EUR/USD position, and the figures exclude financing and execution differences. Neither row describes a particular broker's current prices.
| Account | Spread cost | Round-trip commission | Combined estimate |
|---|---|---|---|
| A: 1.2-pip spread | $1.20 | $0 | $1.20 |
| B: 0.8-pip spread | $0.80 | $0.60 | $1.40 |
Account B's narrower quote does not make it the cheaper account under these assumptions. Change either the spread or the commission and the result may change. The FBS vs XM account comparison applies this approach to reading broker offers without claiming that a quoted minimum spread is the cost every trader will receive.
Why scalpers need to pay close attention
Suppose a setup anticipates a five-pip rise on a bid-price chart. With an unchanged 0.8-pip spread, buying at the ask and closing after that bid-price rise leaves about 4.2 pips before other charges. With a two-pip spread, it leaves about three pips. The intended market move is identical; the amount available to the trader is not.
This example measures the move from the starting bid. If you instead set a five-pip target from your actual entry price, that is a different calculation and the market must travel farther. Define what your target measures before comparing strategy results. Our London Open scalping guide and stop-loss guide explain how entry, invalidation and costs fit together.
Why variable spreads change
Floating spreads can change with liquidity, market uncertainty and the provider's pricing. Check your own instrument around the times you plan to trade, including the market reopening, financing rollover and important announcements. A quiet average can hide brief periods when a small-target strategy becomes expensive to execute.
A wider spread is a reason to re-evaluate the trade's economics, not evidence of an opportunity to collect the spread. OANDA's historical-spread tool is an example of looking at observed pricing over time; its data describes its own offering and should not be treated as a measurement of another broker.
Build a useful comparison record
- Choose a consistent comparison. Use the same pair, account currency, position size and trading session. Note whether the account is Standard, Cent, Micro or commission-based.
- Record quotes at relevant times. Save the bid and ask, not just a minimum spread from a website. Include occasions when you would reject the setup because costs are too high.
- Add the applicable charges. Convert commissions into the same currency and use the expected holding period for financing. Keep requested and actual fill prices separate.
- Assess the strategy after costs. Check whether its average wins and losses still make sense. Reducing costs helps the arithmetic but does not create a profitable entry method by itself.
A well-defined cost record is more useful than repeatedly searching for a “zero spread” promise. Once you know what a normal trade costs, you can see whether the problem lies in pricing, execution, position size or the strategy's underlying expectancy.
Check the spread against your own completed trades
A quote snapshot can explain the entry cost, but it does not by itself establish the full cost of a completed position. When comparing account types or evaluating a scalping idea, include commissions, overnight financing when relevant and the difference between requested and filled prices. The after-cost trading-strategy audit shows how these assumptions change a result.
If you use MetaTrader 4, follow the guide to export MT4 trade history to Excel. Keep the original report so that your spreadsheet calculations can be checked against the broker statement.
Sources and review scope
- OANDA: bid and ask prices — Definitions of the quoted buy and sell prices and their spread.
- OANDA: what is a pip? — Pip conventions and their use in forex calculations.
- OANDA: historical spreads — A provider-specific example of observing spread costs over time, not a cross-broker ranking.
- ASIC Moneysmart: CFD costs and risks — Distinguishes commissions, spreads, financing and execution risk.
Follow the related learning path in Risk and Broker Safety.
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