A pip is a conventional unit for measuring a change in an exchange rate, while the spread is the difference between the bid and ask price available for a currency pair. Pips describe movement; spreads are one part of transaction cost. Neither should be treated as a complete measure of trading risk until the movement is translated into money for the actual position size.
What a pip measures
Many currency pairs use a standard decimal convention in which one pip corresponds to a small fixed change in the quoted exchange rate. Some pairs use a different decimal convention, and many platforms display an extra fractional digit beyond the standard pip.
The important point is not memorising one decimal rule for every instrument. The trader should know the pip size for the pair being traded and confirm how the broker displays price precision.
Pip value depends on the position
The same number of pips can represent very different amounts of money. Monetary pip value depends on the pip size, the number of currency units in the position and, where necessary, conversion into the account currency.
A useful high-level relationship is:
Pip value = pip size × position units, with currency conversion applied when the resulting value is not already expressed in the account currency.
This is why “I lost 20 pips” says less about risk than “I lost the amount I had planned to risk.” Position size determines whether a small movement is financially minor or significant.
What the bid-ask spread means
The bid is the price at which the market or broker is willing to buy from the trader, while the ask is the price at which it is willing to sell to the trader. The difference between them is the spread.
If a trader opens and immediately closes a position with no market movement, the bid-ask difference creates a cost before commissions, financing or slippage are considered. A narrow displayed spread can therefore be useful, but it is not the whole cost of execution.
Spread cost should be measured in money
A practical approximation for a linear FX position is:
Spread cost ≈ spread in pips × monetary pip value.
If the spread widens while the position size stays the same, the immediate transaction cost rises. If the position size doubles, the monetary effect of the same spread also doubles.
This is one reason position sizing, transaction cost and execution should be reviewed together rather than as separate topics.
Why spreads change
Spreads are not fixed properties of a currency pair. They can change with available liquidity, time of day, volatility, event risk and the broker or venue providing the quote. A pair that normally trades with a relatively tight spread can widen during a rapid repricing or when fewer participants are willing to provide liquidity.
Forex Liquidity explains why transaction conditions can deteriorate even when a pair is usually considered liquid.
Spread is not the same as slippage
The spread is visible in the difference between bid and ask quotes. Slippage is the difference between an expected execution price and the actual fill. They are related to execution quality but they are not the same thing.
A strategy can face a normal-looking spread and still experience slippage when the market moves quickly or when available liquidity at the expected price is insufficient. Conversely, a wider spread can be visible before an order is sent.
Commissions and financing also matter
Some brokers charge a separate commission instead of embedding most trading cost in the spread. Leveraged positions held across financing periods can also incur or receive financing adjustments depending on the product and broker terms.
For system testing, transaction cost should therefore include the costs that actually apply to the account rather than one generic spread assumption. A backtest that ignores realistic cost can overstate how attractive a strategy would have been in practice.
How pips connect to stop distance and position size
A stop measured in pips is only a price distance. To turn it into account risk, the trader needs the pip value and the number of units in the position.
For a simple linear FX position:
Planned monetary loss ≈ stop distance in pips × pip value, before allowing for spread changes, slippage or gaps.
The general Position Sizing framework explains how a predefined risk amount is converted into exposure. The FX-specific calculation adds pair quotation and pip value.
Common mistakes with pips and spreads
- comparing trades by pip count without comparing monetary risk;
- assuming the displayed spread is the complete trading cost;
- using a fixed historical spread in testing when live spreads vary;
- forgetting that position size changes pip value;
- ignoring currency conversion when the pip value is not in the account currency; and
- treating a stop price as a guaranteed execution price.
Pips and spreads inside the MFXG forex framework
Currency Pairs explains the quotation that produces the price movement. Foreign Exchange provides the broader market context, while Risk Management explains why transaction cost and stop distance must fit inside the account's risk budget.
The practical rule is to translate everything into account impact. Pips make price movement easy to describe, but monetary risk is what determines whether a trade is appropriately sized.