In retail currency trading, market participants often wonder how brokerage firms generate revenue, especially when many advertise “zero commission” trading accounts. The answer lies in the price quotation structure: specifically, the Bid price, the Ask price, and the difference between them, known as the Spread. Understanding transaction costs is critical for evaluating trading strategies, especially for short-term and intraday methodologies.
1. Defining the Bid and Ask Prices
Whenever you open your charting software or broker terminal, every currency pair displays two prices simultaneously:
- The Bid Price: The price at which the broker (and market) is willing to buy the base currency from you. This is the price you receive when you open a Sell (Short) position.
- The Ask (or Offer) Price: The price at which the broker is willing to sell the base currency to you. This is the price you pay when you open a Buy (Long) position.
The Ask price is always higher than the Bid price. This disparity exists across all two-sided financial markets, from local foreign exchange booths at airports to institutional interbank networks.
2. What is the Spread?
The Spread is simply the difference between the Ask price and the Bid price, typically measured in pips:
Spread = Ask Price – Bid Price
For example, if EUR/USD is quoted as Bid: 1.0850 / Ask: 1.0852:
- The spread is 1.0852 – 1.0850 = 0.0002 (2.0 pips).
- If you open a Buy trade of 1 standard lot at the Ask price (1.0852), your trade will immediately begin with a floating unrealized loss of -$20.00 (the 2 pips spread). The market must advance by 2 pips in your favor simply to reach the break-even point.
3. Fixed vs. Variable (Floating) Spreads
Brokers provide spreads through two primary models:
| Spread Model | Characteristics | Pros & Cons |
|---|---|---|
| Fixed Spreads | The spread remains constant regardless of market conditions or time of day. | Predictable costs; however, prone to requotes during volatile news releases. |
| Variable (Floating) Spreads | The spread fluctuates dynamically based on interbank market liquidity and volatility. | Extremely tight during peak market hours; expands significantly during news releases and off-hours. |
4. What Causes Spreads to Widen?
In floating spread environments, several market conditions cause spreads to expand dramatically:
- High-Impact Economic News: During announcements like US Non-Farm Payrolls (NFP) or Interest Rate decisions, liquidity providers pull quotes, causing spreads to jump from 1 pip to 10+ pips within seconds. Learn more in How to Read an Economic Calendar.
- Market Session Rollover (5:00 PM EST): When the New York session closes and the trading day rolls over, liquidity dries up for 30-60 minutes, leading to temporary spread spikes. Check our guide on The 4 Major Forex Market Sessions.
- Exotic Currency Pairs: Pairs involving less liquid emerging market currencies (e.g., USD/ZAR or USD/TRY) inherently carry wide spreads compared to major pairs like EUR/USD.
5. Additional Trading Costs: Swaps and Commissions
Beyond the spread, market participants must factor in two other potential costs:
- Commissions: Direct fees charged per lot, common on ECN or Raw Spread accounts where spreads are near zero.
- Rollover / Swap Fees: Interest adjustments credited or debited to your account when holding positions overnight, based on the interest rate differential between the base and quote currencies.
Educational Disclaimer: This publication is strictly educational and does not constitute financial or brokerage advice. Trading foreign currencies involves significant financial risk. Please review our Financial & Risk Disclaimer before participating in live trading.