Risk Warning: CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. Between 74–89% of retail investor accounts lose money when trading CFDs. You should consider whether you understand how CFDs work and whether you can afford to take the high risk of losing your money.
Bid-ask spread analysis is the study of the difference between the bid price (the highest price a buyer will pay) and the ask price (the lowest price a seller will accept) as a source of trading intelligence. The bid-ask spread is simultaneously the trader’s direct transaction cost and a real-time signal about market liquidity, volatility, institutional activity, and session conditions. Analysing how the spread widens and narrows — and under what circumstances — helps traders optimise their entry and exit timing, identify high-risk market conditions, choose the most cost-efficient brokers, and detect early signals of changing market dynamics that precede significant price moves.
What Is the Bid-Ask Spread?
Every financial instrument in any traded market has two prices at any given moment:
- The Bid: The highest price that a buyer in the market is currently willing to pay for the instrument
- The Ask (or Offer): The lowest price that a seller in the market is currently willing to accept
The bid-ask spread is the difference between these two prices:
Spread = Ask Price − Bid Price
For example: EUR/USD is quoted as 1.08501 / 1.08512. The bid is 1.08501 and the ask is 1.08512. The spread is 1.1 pips (0.00011).
This spread is not a fee charged by your broker in the traditional sense — it is the natural gap between the best available buyer and the best available seller in the market. However, it represents a direct cost to the trader: if you buy at the ask and immediately sell at the bid, you have lost the spread. The market must move in your favour by at least the spread amount before you break even on any trade.
For this reason, the bid-ask spread is simultaneously:
- A transaction cost — directly reducing your profit on every trade
- A market microstructure signal — revealing information about liquidity, volatility, and institutional activity
Understanding and analysing both dimensions is the essence of bid-ask spread analysis.
Bid, Ask, and Mid Price: Definitions
The Bid Price
The bid price is the highest price any market participant is currently willing to pay to buy the instrument. When you enter a sell (short) order at market price, your order executes at the bid — the best available buyer.
The Ask Price (Offer)
The ask price is the lowest price any market participant is currently willing to accept to sell the instrument. When you enter a buy (long) order at market price, your order executes at the ask — the best available seller.
The Mid Price (Midpoint)
The mid price is the arithmetic average of the bid and ask:
Mid Price = (Bid + Ask) / 2
Many financial data providers and charting platforms display mid prices on their charts. This can create a subtle discrepancy: if EUR/USD is 1.08501/1.08512, the chart shows 1.085065 (the mid), but your buy order executes at 1.08512 (the ask). Your actual entry will always be slightly different from the charted price — by exactly half the spread for a mid-price chart.
This is an important practical point: when backtesting strategies or reviewing trades, always account for the bid-ask spread. A strategy that appears profitable on a mid-price chart may be much less so (or even unprofitable) when the actual execution cost of buying at the ask and selling at the bid is factored in.
What Causes the Bid-Ask Spread?
The bid-ask spread exists for three interconnected reasons: liquidity, volatility, and market maker compensation.
Liquidity
Liquidity refers to how easily and quickly an instrument can be bought or sold without significantly moving the price. Highly liquid instruments — EUR/USD, major government bonds, large-cap equities — have an enormous number of buyers and sellers constantly competing to transact. This competition narrows the gap between the best bid and best ask.
Less liquid instruments — exotic currency pairs, small-cap stocks, thinly traded CFDs — have fewer competing participants. With fewer buyers and sellers, the best bid may be significantly below the best ask, resulting in a wider spread.
The liquidity principle: More participants = more competition = narrower spread.
Volatility
Volatility is the speed and magnitude of price changes. When price is moving rapidly — during news events, market opens, or periods of uncertainty — market makers (who are on the other side of most retail transactions) face a greater risk of being caught with a position that moves against them before they can hedge it. To compensate for this elevated risk, they widen the spread.
During calm, low-volatility sessions, market makers have more time to hedge their exposure and the spread narrows.
The volatility principle: Higher volatility = wider spread; lower volatility = narrower spread.
Market Maker Compensation
In markets where market makers are the primary liquidity providers — including the retail forex market — the spread is the market maker’s primary source of compensation. By quoting a slightly higher ask (from which they sell to buyers) and a slightly lower bid (at which they buy from sellers), market makers earn the difference on every transaction processed.
ECN/STP brokers that connect traders directly to interbank liquidity providers reduce or eliminate the market maker’s spread, instead charging a fixed commission per trade. This typically results in lower total costs for active traders. Compare ECN brokers at Best ECN Brokers 2026 on CompareBroker.io.
Fixed vs Variable Spreads
Variable (Floating) Spreads
Variable spreads change continuously in real time, reflecting the underlying liquidity conditions of the market. They are narrowest during high-liquidity sessions (London/New York overlap on major forex pairs) and widest during low-liquidity periods (Asian overnight session, weekends, news events).
Advantages: Variable spreads can be very tight (sometimes 0.0–0.3 pips on EUR/USD during peak hours at ECN brokers), providing the lowest possible transaction cost during optimal conditions.
Disadvantages: They can widen dramatically — sometimes to 3–10× their normal width — during news events, low-liquidity periods, or market dislocations, making trade execution unpredictable in terms of cost.
Fixed Spreads
Fixed spreads remain constant regardless of market conditions. A broker offering a fixed 1.5-pip spread on EUR/USD maintains that spread throughout all sessions — during news events, during the Asian session, and during the London open.
Advantages: Predictable, consistent transaction cost. Particularly useful for traders who prefer cost certainty over potentially lower but variable costs.
Disadvantages: Fixed spreads are typically wider than variable spreads during the best market conditions. A fixed 1.5-pip spread is more expensive than a 0.2-pip variable spread during peak liquidity — but cheaper than a 3-pip variable spread during a news spike.
Compare brokers with the lowest fixed spreads at Compare Fixed Spread Brokers and Compare Zero Spread Brokers on CompareBroker.io.
How Spread Affects Trading Costs
The spread’s impact on profitability depends entirely on your trading style and target profit per trade.
Spread as a Percentage of Target
Trading Style | Typical Target | Typical Spread (EUR/USD) | Spread as % of Target |
Scalper | 5–10 pips | 0.5–1 pip | 5–20% |
Day trader | 20–50 pips | 0.5–1 pip | 1–5% |
Swing trader | 60–150 pips | 0.5–1 pip | 0.3–1.7% |
Position trader | 200–500 pips | 0.5–1 pip | 0.1–0.5% |
The implication is stark: For scalpers targeting 5–10 pips per trade, a 1-pip spread represents 10–20% of the profit target on every single trade. This is why scalpers are the traders most sensitive to spread costs and why they prioritise ECN brokers with the tightest possible spreads.
For swing traders targeting 100+ pips, the same 1-pip spread is a negligible percentage of the target. Cost sensitivity decreases as trade duration and target increase.
Round-Turn Cost Calculation
The true spread cost of a trade is calculated on both entry (buying at the ask, not the mid) and exit (selling at the bid). The total spread cost per round-turn trade is therefore:
Total Spread Cost = Spread × Lot Size
For a 1-pip spread on a standard lot (100,000 EUR/USD units), 1 pip = $10. For a micro lot (1,000 units), 1 pip = $0.10. For beginners using cent accounts, the per-pip value is even smaller, making spread cost practically negligible.
Spread as a Market Signal
Beyond its role as a transaction cost, the bid-ask spread is a powerful real-time signal about market conditions. Monitoring spread behaviour — how it widens, narrows, and changes character — provides information invisible on any standard price chart.
Narrowing Spread = Increasing Liquidity
When the spread narrows significantly (e.g., from 1.2 pips to 0.4 pips on EUR/USD), it signals increasing market liquidity — more buyers and sellers competing, tighter competition for trades. This typically occurs at the London session open and at the London/New York overlap — the highest-activity periods of the forex trading day.
Implication: Narrowing spreads indicate improving conditions for trade execution. Lower costs per trade and better price discovery.
Widening Spread = Decreasing Liquidity or Rising Uncertainty
When the spread widens suddenly (e.g., from 0.5 pips to 3 pips), it signals either:
- Declining liquidity (approaching weekend, end of New York session, Asian overnight hours)
- Rising uncertainty (an impending news event, geopolitical development, or sudden market stress)
- Market stress (a flash crash or unexpected major event causing liquidity providers to temporarily withdraw)
Implication: Wide spreads warn traders to either reduce position sizes, use limit orders rather than market orders (to avoid paying the wide spread), or avoid trading altogether until normal conditions return.
Spread Widening Before Major News
In the minutes preceding a major scheduled economic release (Non-Farm Payrolls, central bank rate decisions, CPI data), spreads on affected currency pairs typically begin widening as market makers pull their tightest quotes and widen their pricing to protect themselves from adverse selection risk.
This pre-news spread widening is itself a signal: it tells traders that the market expects significant volatility around the upcoming release. Traders watching spread changes in real time can use this as an early warning system for incoming volatility — often before the news is formally released.
Spread and Volume Spread Analysis (VSA)
In VSA, the “spread” refers to the range of a price bar (high minus low) — different from the bid-ask spread. However, the two concepts are related: during periods of high market activity and narrow bid-ask spreads, VSA bar spreads (ranges) tend to be wider as price moves more freely. During thin markets with wide bid-ask spreads, VSA bar ranges tend to be narrower.
Spread Behaviour Across Market Sessions {#sessions}
Understanding how spreads behave across the 24-hour forex trading cycle is essential for timing trades cost-efficiently.
Session | Typical EUR/USD Spread (ECN) | Liquidity Level | Notes |
Sydney open (22:00–00:00 GMT) | 0.8–1.5 pips | Low | Widest of the daily cycle on most pairs |
Tokyo/Asian session (00:00–08:00 GMT) | 0.5–1.0 pips | Moderate | Yen pairs tightest; EUR/USD wider than London |
London open (07:00–09:00 GMT) | 0.3–0.6 pips | Very high | Rapid tightening as European banks open |
London/NY overlap (12:00–17:00 GMT) | 0.1–0.4 pips | Maximum | Tightest spreads of the day on major pairs |
New York afternoon (17:00–22:00 GMT) | 0.4–0.8 pips | Declining | Spreads widening as London closes |
Weekend/rollover | 3–10+ pips | Near-zero | Avoid market orders entirely |
The practical implication: The best timeframe for trading execution from a spread-cost perspective is during the London/New York overlap (12:00–17:00 GMT), where the tightest spreads on major pairs are available. Scalpers in particular should only operate during this window when executing on variable-spread ECN accounts.
Spread Behaviour Around News Events {#news}
Major scheduled economic news releases create predictable spread behaviour:
Pre-announcement (30–60 minutes before): Spreads begin widening gradually as liquidity providers reduce their risk exposure.
Immediate announcement: Spreads can widen to 3–15× their normal width in the seconds around the release as liquidity providers temporarily withdraw quotes, market orders flood in, and price makes its initial reaction.
Post-announcement (1–5 minutes after): Spreads normalise as liquidity returns and the initial volatility subsides.
The risk for traders: A stop-loss order triggered during a news-event spread spike may execute at a dramatically worse price than expected — experiencing significant slippage due to both the price gap and the wider spread. This is a significant risk for scalpers and intraday traders who hold positions through news events.
The risk management response:
- Avoid placing market orders in the 5–10 minutes around major news releases
- Use limit orders where possible to control execution price
- Widen stop-losses appropriately to account for expected spike volatility
- For scalping strategies, exit positions before news rather than risk being caught in the spike
Spread Analysis for Entry and Exit Timing
Optimal Entry Timing
From a spread-cost perspective, the optimal time to enter a trade is when:
- The spread is near its daily minimum (London/NY overlap for forex majors)
- The market is not approaching a major news event
- Volatility is sufficient to support your trade’s target without being excessively elevated
Using Limit Orders to Avoid the Spread
Instead of entering with a market order (which always pays the spread), a limit order can be placed inside the spread — at a price between the current bid and ask. In liquid markets, such orders can be filled without paying the full spread. However, there is no guarantee of fill — the order may not be executed if price doesn’t reach your specified level.
Spread Monitoring During Position Management
Once in a trade, monitoring the spread helps with exit timing:
- If the spread suddenly widens dramatically while you are in profit, consider taking profit with a limit order rather than a market order to avoid paying the wide spread
- If a stop-loss is triggered during a wide-spread period, the actual fill may be worse than the stop-loss level (negative slippage) — account for this in risk calculations
Bid-Ask Spread in Order Flow and DOM Analysis
In order flow trading and DOM analysis, the bid-ask spread plays a specific role:
The spread as a microstructure indicator:
- A narrowing spread (bid and ask converging) can signal reduced uncertainty and building consensus — often preceding a directional move
- A sudden spread widening without a news event can signal that a large institution is executing a large order and liquidity providers are widening to protect themselves
DOM and spread interaction:
- When the DOM shows a very large ask order close above the current price, the effective spread for buyers is wider (they must lift through that large offer). This is “phantom spread” — the real cost of transacting is wider than the nominal bid-ask spread
- When large orders are absorbed in the DOM and the bid-ask narrows back, it signals the resistance is giving way and price can move with lower friction
Footprint charts and spread:
- During wide-spread periods, footprint charts show fewer transactions at each price level — less activity overall
- During tight-spread periods, footprint shows denser transaction clusters — more institutional and retail participation
Spread and Broker Selection
The bid-ask spread is one of the most important factors in broker selection — particularly for active traders. Here is how spread considerations map to trading style:
Trading Style | Spread Priority | Recommended Broker Type |
Scalper (5–15 pip targets) | Maximum priority | ECN broker with raw spreads, lowest possible commission |
Day trader (20–80 pip targets) | High priority | ECN or tight-spread market maker |
Swing trader (60–200 pip targets) | Moderate priority | Any regulated broker with competitive spreads |
Position trader (200+ pips) | Low priority | Any regulated broker |
For scalpers: Every 0.1-pip difference in spread costs real money at scale. A scalper executing 20 round-turn trades per day on a standard lot with a 0.5-pip spread pays $100/day in spread costs. The same scalper with a 0.2-pip spread pays $40/day — a difference of $60/day or $15,000+ per year.
This is why scalpers exclusively use ECN brokers with raw spreads and transparent commission structures. Compare the best options at Best Scalping Brokers 2026 and Best ECN Brokers 2026 on CompareBroker.io.
How to Compare Spreads Across Brokers
Comparing spreads between brokers requires care — advertised spreads can be misleading.
Typical vs Minimum Spread
Most brokers advertise their minimum spread (e.g., “EUR/USD from 0.0 pips”) — achievable only during peak liquidity conditions. The typical or average spread reflects real-world conditions across all sessions. Always check the typical spread, not just the headline minimum.
Spread + Commission vs All-In Spread
ECN brokers typically charge: raw spread (0.0–0.3 pips) + commission per lot (e.g., $3.50/side on a standard lot = $7 round-turn). Market makers charge: all-in spread (no commission) but wider spread (e.g., 0.8–1.2 pips on EUR/USD).
To compare the true cost, calculate the all-in spread equivalent: ECN: 0.1 pip spread + $7 commission per standard lot = $8 round-turn. At $10/pip = 0.8-pip all-in equivalent. Market maker: 1.0-pip all-in spread = $10 round-turn.
In this example, the ECN is cheaper overall. But on smaller lot sizes (micro/cent accounts), the commission can dominate and make market maker spreads more competitive.
Tools for comparison:
- Compare Zero Spread Brokers — brokers with raw ECN spreads
- Compare Fixed Spread Brokers — predictable cost structures
- Best ECN Brokers 2026 — full ECN broker analysis
- How to Compare Forex Brokers — complete cost evaluation framework
Frequently Asked Questions
What is the bid-ask spread in forex? The bid-ask spread in forex 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). It represents the immediate transaction cost of opening a trade and is also a real-time indicator of market liquidity and volatility conditions.
Why does the bid-ask spread widen during news events? During major news releases, uncertainty about the next price direction increases dramatically. Liquidity providers and market makers widen their spreads to protect themselves from the risk of being caught on the wrong side of a large, sudden price movement. With fewer participants willing to transact at tight spreads, the gap between the best available bid and ask expands significantly.
Is a smaller bid-ask spread always better? A smaller spread means lower transaction costs, which is better from a pure cost perspective. However, extremely tight spreads that occur only during brief peak-liquidity windows may not be representative of average trading conditions. Always evaluate the typical spread across a full session — not just the minimum achievable spread — when comparing brokers.
What is the best time of day for tight spreads in forex? The tightest spreads on major forex pairs (EUR/USD, GBP/USD, USD/JPY) occur during the London/New York overlap session, approximately 12:00–17:00 GMT. This is the highest-liquidity window of the trading day and when ECN brokers’ raw spreads are at their absolute minimum.
How does the spread affect scalping? The spread is the single most important cost factor for scalpers because it represents a large percentage of the small profit target per trade. A scalper targeting 5 pips per trade with a 1-pip spread must generate a 1-pip move just to break even — 20% of the target. This is why scalpers exclusively use ECN brokers with the lowest available spreads. Compare options at Best Scalping Brokers 2026.
What is a zero-spread broker? A zero-spread broker offers raw interbank spreads that can reach 0.0 pips on major pairs during peak liquidity. These brokers charge a separate commission per trade instead of including profit in the spread. They are ideal for scalpers and high-frequency day traders but require careful cost calculation (spread + commission vs all-in spread). Compare options at Compare Zero Spread Brokers.
Risk Warning: Trading CFDs and forex involves significant risk of loss. This article is for educational purposes only and does not constitute investment advice. Always trade with a regulated broker and only risk capital you can afford to lose.
