How Do Spread and Commission Work in Forex Trading?

When trading foreign exchange, entering and exiting positions is rarely free. Brokers charge fees for facilitating your access to global liquidity, and these trading costs primarily take two forms: spreads and commissions.

Understanding how both mechanisms work is crucial because transaction costs directly impact your profitability—especially if you trade frequently using day-trading or scalping strategies.

What is a Spread in Forex Trading?

The spread is the difference between the Bid price (the price at which you can sell) and the Ask price (the price at which you can buy) of a currency pair.

+-------------------------------------------------------+
|  EUR/USD                                              |
|  BID: 1.0850                  ASK: 1.0852             |
|  (Price to Sell)              (Price to Buy)          |
|                                                       |
|             Spread = 1.0852 - 1.0850                  |
|                    = 0.0002 (2 Pips)                  |
+-------------------------------------------------------+

When you open a trade, you instantly buy at the higher Ask price or sell at the lower Bid price. Because of this gap, every trade begins with a small floating loss equivalent to the spread.

How Spread is Calculated

Spread is measured in pips (or fractionally in pipettes).

Example: If EUR/USD is quoted as Bid: 1.0850 / Ask: 1.0852, the spread is 2 pips.

• On a Standard Lot ($100,000$ units), where 1 pip = $\$10$, the transaction cost is:

  $$\text{Spread Cost} = 2 \text{ pips} \times \$10 = \mathbf{\$20.00}$$

Variable Spreads vs. Fixed Spreads

Brokers typically offer two types of spread structures:

Note: Variable spreads usually widen significantly during low-liquidity periods (like market roll-overs) or right before major economic announcements.

What is a Commission in Forex Trading?

While a spread is built directly into the exchange rate price, a commission is a separate, flat fee charged by the broker per lot traded. Commissions are typically billed on a round-turn basis (covering both entering and exiting the trade).

• Example Structure: A broker might charge a commission of $3.50 per lot per side ($7.00 round-turn for every standard lot traded).

Commissions are most common on ECN (Electronic Communication Network) or STP (Straight-Through Processing) accounts, where the broker passes raw interbank spreads directly to the trader without adding a markup.

Comparing Broker Pricing Models: Standard vs. Raw/ECN Accounts

Forex brokers generally divide their account offerings into two pricing structures based on how spreads and commissions interact:

+-------------------------------------------------------------------------+
|                        Forex Broker Account Models                      |
+-------------------------------------------------------------------------+
|  1. Standard Account (Spread-Only)                                      |
|     • Spreads: Marked-up (e.g., 1.2 pips)                               |
|     • Commission: $0                                                    |
|                                                                         |
|  2. ECN / Raw Spread Account (Raw + Commission)                          |
|     • Spreads: Direct Raw Interbank (e.g., 0.1 pips)                     |
|     • Commission: Fixed fee (e.g., $7 per round-turn standard lot)      |
+-------------------------------------------------------------------------+

Side-by-Side Cost Comparison Example

Let’s compare trading 1 Standard Lot ($100,000$ units) of EUR/USD across both account types:

In this scenario, trading on the Raw/ECN Account saves $4.00 per trade, despite having an explicit commission charge.

Key Takeaways for Traders

1. Calculate Total Cost: Never look at spreads or commissions in isolation. Always combine them into a single metric:

   $$\text{Total Cost} = \text{Spread Cost} + \text{Commission Fee}$$

2. Strategy Alignment:

   • Scalpers & Day Traders: Benefit significantly from Raw/ECN accounts with low spreads, as tight entries are vital for short-term profits.

   • Swing & Position Traders: Holding trades for days or weeks means minor spread differences matter far less than overall broker reliability and swap rates.