What Is the Bid-Ask Spread? How It Affects Your Trading Costs
Every time you open a trade, you pay a cost before the market even moves — the spread. It is the most overlooked expense in trading, especially for beginners who focus only on commissions. Understanding the bid-ask spread is one of the fastest ways to stop leaking money on every position.
Bid, ask, and the gap between them
At any moment a market shows two prices:
The spread is simply the difference: ask minus bid. The ask is always slightly higher than the bid, and that gap is what market makers and liquidity providers earn for being willing to trade with you on demand.
Why it is a cost you pay immediately
Because you buy at the ask and later sell at the bid, you start every trade slightly underwater. If EUR/USD is quoted 1.1620 / 1.1621, you buy at 1.1621 but could only sell back at 1.1620 — a 1-pip spread. Price has to move at least that far in your favor just to break even. On a short-term scalp, the spread can be a meaningful chunk of your target; on a multi-day swing trade, it is almost negligible. That is why spread matters far more to high-frequency styles than to position traders.
What makes spreads wider or tighter
Fixed vs variable spreads
Some brokers offer fixed spreads that stay constant regardless of conditions, which makes costs predictable but can be wider on average. Others offer variable (floating) spreads that track the live market — usually tighter in calm conditions but capable of widening sharply during news. Neither is universally "better"; it depends on when and how you trade.
How to keep the spread from eating your edge
The spread is unavoidable, but it is manageable. Treat it as a fixed tax on every trade, account for it in your plan, and you will stop being surprised by the small, constant drag it puts on your results.
This article is educational and not financial advice. Always check the live spread and total costs with your own broker.
Every time you open a trade, you pay a cost before the market even moves — the spread. It is the most overlooked expense in trading, especially for beginners who focus only on commissions. Understanding the bid-ask spread is one of the fastest ways to stop leaking money on every position.
Bid, ask, and the gap between them
At any moment a market shows two prices:
- Bid — the price at which you can sell (the highest price buyers are willing to pay).
- Ask (or offer) — the price at which you can buy (the lowest price sellers are willing to accept).
The spread is simply the difference: ask minus bid. The ask is always slightly higher than the bid, and that gap is what market makers and liquidity providers earn for being willing to trade with you on demand.
Why it is a cost you pay immediately
Because you buy at the ask and later sell at the bid, you start every trade slightly underwater. If EUR/USD is quoted 1.1620 / 1.1621, you buy at 1.1621 but could only sell back at 1.1620 — a 1-pip spread. Price has to move at least that far in your favor just to break even. On a short-term scalp, the spread can be a meaningful chunk of your target; on a multi-day swing trade, it is almost negligible. That is why spread matters far more to high-frequency styles than to position traders.
What makes spreads wider or tighter
- Liquidity — heavily traded markets like EUR/USD or major indices have very tight spreads; thin, exotic, or low-volume instruments have wide ones.
- Time of day — spreads tighten during active sessions (e.g. the London–New York overlap) and widen during quiet hours like the late-evening rollover.
- Volatility and news — around major data releases, spreads can blow out dramatically as liquidity providers pull back to protect themselves.
- Account type — "commission-free" accounts often bake their fee into a wider spread, while raw-spread accounts show tighter spreads but charge a separate commission. Compare the all-in cost, not just one number.
Fixed vs variable spreads
Some brokers offer fixed spreads that stay constant regardless of conditions, which makes costs predictable but can be wider on average. Others offer variable (floating) spreads that track the live market — usually tighter in calm conditions but capable of widening sharply during news. Neither is universally "better"; it depends on when and how you trade.
How to keep the spread from eating your edge
- Trade liquid instruments during active hours whenever possible.
- Avoid entering right into a major news release unless that is your deliberate strategy — spreads (and slippage) are at their worst then.
- Factor the spread into your target: a 5-pip target with a 2-pip spread is a very different trade than it looks.
- Compare brokers on total cost (spread + commission), not marketing headlines.
The spread is unavoidable, but it is manageable. Treat it as a fixed tax on every trade, account for it in your plan, and you will stop being surprised by the small, constant drag it puts on your results.
This article is educational and not financial advice. Always check the live spread and total costs with your own broker.