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What is Spread in forex and CFD trading

The Spread is the difference between the 賣出價 (the price a trader buys at) and the 買入價 (the price a trader sells at) for a given currency pair or CFD instrument. The Spread matters for real trading decisions because it represents the direct and immediate cost of opening a position, meaning a trade must move favorably by at least the value of the Spread before it can reach the breakeven point. A trader can verify or measure the current Spread on their platform by viewing the difference between the two quoted prices in the Market Watch window, often measured in pips or points. For more terms like this, visit our 外匯術語表.

Key facts about Spread

• 定義： Spread is the gap between the highest price a buyer is willing to pay (Bid) and the lowest price a seller is willing to accept (Ask).
• Cost Metric: The Spread is the broker’s primary fee for trade execution in a no-commission account, or a cost component in a commission-based account.
• 公式： Spread = Ask Price – Bid Price.
• Units: The Spread is typically measured in pips or points, with 1 pip being 0.0001 for most FX pairs, or 0.00001 for 5 decimal brokers.
• Variability: Spreads can be fixed (offered by some market makers, non-variable) or variable (changing dynamically with market liquidity and volatility, common in ECN brokers).
• Liquidity Relation: High liquidity generally results in a tight spread (low cost), while low liquidity, such as during news events or off-peak hours, results in a wide spread (high cost).

How Spread works in forex and CFD trading

The Spread works as the mechanism through which the liquidity provider or broker generates profit while facilitating the trade, acting as a frictional cost to the trader.

該流程包含以下操作步驟：

1. Quote Aggregation: The broker receives real-time quotes, the highest Bid price and the lowest Ask price, from its liquidity sources.
2. Price Display: Both prices are displayed to the trader, and the Spread is instantaneously calculated as the difference between them.
3. Entry Cost: When a trader initiates a long position (Buy), it is executed at the Ask price but the position is valued instantly at the lower Bid price, creating an immediate loss equal to the value of the Spread.
4. Cost Recovery: For the trade to become profitable, the market price must move past the initial Ask price by a distance greater than the value of the Spread.
5. Dynamic Adjustment: In a variable Spread model, the difference between the Ask and Bid widens during periods of high volatility or thin liquidity to account for increased market risk.

Example of Spread with a real trade

This example shows how the Spread constitutes the initial cost of entering a long position on EUR/USD.
Instrument: EUR/USD Quoted Price: Bid 1.10000 / Ask 1.10008 Position size: 1 standard lot (100,000 units)
Calculate Spread: Ask Price – Bid Price = 1.10008 – 1.10000 = 0.00008 Spread in Pips: The Spread is 0.8 pips. Calculate Cost in Currency: Spread (in pips) × Pip Value × Lots = 0.8 × $10/pip × 1 = $8.00 Initial PnL: A trader executing a Buy at 1.10008 sees an immediate floating PnL of -$8.00, as the position is instantly valued at the Bid price of 1.10000.
Result: The initial transaction cost, or immediate loss, resulting from the Spread is $8.00. Note that with Afterprime’s zero commission structure, this spread cost is the only transaction fee—there are no additional per-trade commission fees compounding the entry cost.

How Spread affects your cost and risk

The Spread is the first cost of trading, directly reducing the potential PnL and increasing the price distance required for a trade to become profitable.

Spread compared with related concepts

Spread vs Commission

The Spread is the indirect trading cost baked into the price quote, which is paid on every trade regardless of account type, whereas Commission is a direct, flat fee charged by the broker per lot traded, typically only applied in raw ECN accounts where the spreads are near zero.

Spread vs Slippage

The Spread is a predictable, upfront cost visible on the quote, representing the difference between the Bid and Ask at the time of order submission, while Slippage is an unpredictable execution risk where the final fill price differs from the quoted Bid or Ask price, occurring only upon 訂單執行.

Broker differences in Spread across the industry

The Spread is the most variable factor across brokers, depending entirely on the broker’s business model and liquidity arrangements.

How to verify Spread on your trading platform

To mechanically verify the real-time Spread for an instrument on a platform like MetaTrader 5 (MT5), follow these steps:

1. Open Market Watch: Open the Market Watch window in MT5, ensuring the instrument (e.g., EUR/USD) is visible.
2. 顯示分佈欄： Right-click anywhere in the Market Watch window and select Columns, then ensure the Spread column is active.
3. Read Numeric Spread Value: Observe the numeric value displayed in the Spread column, which shows the real-time difference in points (usually 1/10 of a pip).
4. Visualize on Chart: Alternatively, right-click on the chart, select Properties, and enable Show Ask line to visualize the Bid and Ask lines; the vertical gap is the Spread.
5. 手動計算檢查： Open a New Order ticket and manually calculate: Ask Price – Bid Price to confirm the Spread value in pips.
6. Measure Distance on Chart: Use the crosshair tool on the chart to measure the vertical distance between the Ask line and the Bid line in points or pips.

Sanity check: For major pairs during peak hours, the Spread should typically be less than 1.0 pip on an ECN account, or less than 2.0 pips on a standard account.