Bid, Ask & Spread — Complete Mechanics Guide
Master bid-ask spread mechanics. Learn how spreads work, why they matter for your profitability, and how to minimize spread costs across different markets.
Understanding Bid, Ask & Spread
Every time you trade, you encounter the bid-ask spread — the difference between the buying and selling price. This is your first cost of trading and understanding it is essential for profitability.
The spread is an invisible cost that many beginners ignore. On every trade you enter, you start at a LOSS equal to the spread. You must overcome this cost before reaching profit.
Core Definitions
Bid Price
The price at which the market (broker) is willing to BUY from you. This is the price you receive when you SELL.
Ask Price (Offer)
The price at which the market (broker) is willing to SELL to you. This is the price you pay when you BUY.
Spread
The difference between Ask and Bid price: Spread = Ask - Bid
Visual Example:
EUR/USD Quote:
┌─────────────────────────────────────┐
│ BID: 1.0895 │ ASK: 1.0897 │
│ (Sell price) │ (Buy price) │
│ │ │
│ SPREAD: 2 pips │
└─────────────────────────────────────┘
When you BUY: You enter at 1.0897 (Ask)
When you SELL: You enter at 1.0895 (Bid)
Your immediate cost: 2 pips
How Spread Affects Your Trades
Going Long (Buy):
- You BUY at the Ask price (higher)
- To close, you SELL at the Bid price
- Price must move UP by at least the spread to break even
Going Short (Sell):
- You SELL at the Bid price (lower)
- To close, you BUY at the Ask price
- Price must move DOWN by at least the spread to break even
Practical Impact:
| Spread | Required Movement to Break Even | Impact on 10-pip Target |
|---|---|---|
| 0.5 pips | Price must move 0.5 pips | 5% cost |
| 1.0 pips | Price must move 1.0 pips | 10% cost |
| 2.0 pips | Price must move 2.0 pips | 20% cost |
| 5.0 pips | Price must move 5.0 pips | 50% cost |
If your average profit target is 10 pips and the spread is 2 pips, you're paying 20% of your profit to the broker on every trade. Over hundreds of trades, this compounds significantly.
Types of Spreads
Fixed Spread
- Remains constant regardless of market conditions
- Offered by market maker brokers
- Typically wider than variable spreads
- Advantage: Predictable costs
- Disadvantage: Usually higher overall
Variable (Floating) Spread
- Changes based on market liquidity and volatility
- Offered by ECN/STP brokers
- Tighter during high liquidity, wider during low
- Advantage: Often cheaper during active sessions
- Disadvantage: Can widen dramatically during news
Typical Spreads by Market:
| Instrument | Normal Spread | News Spread | Best Session |
|---|---|---|---|
| EUR/USD | 0.6-1.2 pips | 3-8 pips | London/NY overlap |
| GBP/USD | 0.8-1.8 pips | 5-15 pips | London session |
| USD/JPY | 0.7-1.4 pips | 3-10 pips | Tokyo/London |
| Gold (XAUUSD) | 15-30 cents | 50-150 cents | London/NY |
| S&P 500 | 0.3-0.8 points | 2-5 points | US session |
| Bitcoin | $5-30 | $50-200 | Variable |
What Determines Spread Size?
1. Liquidity
- High liquidity = Tight spreads (EUR/USD, USD/JPY)
- Low liquidity = Wide spreads (exotic pairs, small-cap stocks)
2. Volatility
- Low volatility = Tighter spreads
- High volatility = Wider spreads (news events)
3. Trading Session
- Active session (London/NY) = Tightest spreads
- Off-hours (Asian session for EUR pairs) = Wider spreads
- Weekend gaps = Much wider
4. Broker Type
- ECN/STP brokers = Tighter spreads + commission
- Market makers = Wider spreads, no commission
- DMA brokers = Raw institutional spreads + fee
5. Account Type
- Standard accounts = Wider spreads, no commission
- Raw/ECN accounts = Tight spreads + commission per lot
- VIP accounts = Best spreads for high-volume traders
Calculating Spread Cost
Formula:
Spread Cost = Spread (pips) × Pip Value × Position Size
Example:
- Pair: EUR/USD
- Spread: 1.2 pips
- Position: 1 standard lot (100,000 units)
- Pip value: $10
Spread Cost = 1.2 × $10 × 1 = $12 per trade (round trip)
Daily Cost for Active Traders:
Daily Spread Cost = Avg Spread × Pip Value × Lot Size × Number of Trades
Example (Day Trader):
- 5 trades/day × $12 per trade = $60/day
- Monthly: $60 × 22 trading days = $1,320/month
- Yearly: $1,320 × 12 = $15,840/year
A day trader making 5 trades daily on 1 standard lot can pay over $15,000/year just in spreads. This is why choosing a low-spread broker and timing your entries during tight-spread sessions is crucial.
How to Minimize Spread Costs
- Trade major pairs — EUR/USD, USD/JPY have the tightest spreads
- Trade during active sessions — London and NY overlap (8:00-12:00 EST)
- Avoid trading during news — Spreads widen 3-10x during high-impact events
- Use ECN/Raw spread accounts — Pay commission but get tighter spreads
- Consider lot size — Spread cost is per lot; trade appropriate sizes
- Don't scalp exotic pairs — Spreads too wide for small targets
- Compare brokers — Even 0.5 pip difference adds up over thousands of trades
- Use limit orders — You choose the entry price (can enter at bid)
Spread vs. Commission: Which is Better?
| Factor | Spread Only | Raw Spread + Commission |
|---|---|---|
| Total Cost | Often higher | Often lower |
| Transparency | Hidden in spread | Clear, separate fee |
| Scalping | Expensive | Better value |
| Swing Trading | Acceptable | Slight advantage |
| Best For | Beginners (simpler) | Active traders |
Example Comparison:
Spread Only Broker: EUR/USD spread = 1.6 pips → Cost per lot = $16
Raw + Commission Broker: EUR/USD spread = 0.2 pips + $7 commission → Total cost = $2 + $7 = $9
Savings: $7 per trade (43% cheaper)
Related Topics
- Pips, Points & Terminology — Understanding price measurements
- Trading Costs & Spreads — Complete cost analysis
- Order Types — Execute at better prices
- Forex Basics — Market fundamentals
- Position Sizing — Calculate proper lot sizes