Bid-Ask Spread Explained: Why Every Trade Starts at a Loss
There is never one price. There is a price you can sell at and a slightly higher price you can buy at, and the gap between them is the single most reliable cost in trading: you pay it on every trade, win or lose.
In one sentence:
The bid is the best price someone will currently pay you, the ask is the lowest price someone will currently sell to you, and the gap between them is what you pay for the privilege of trading immediately.
The Bid-Ask Spread at a glance
| Bid | The highest price a buyer is currently willing to pay: the price you sell at |
| Ask (or offer) | The lowest price a seller is currently willing to accept: the price you buy at |
| Spread | Ask minus bid, quoted in pips, points, ticks or cents |
| Who receives it | Market makers and liquidity providers, in exchange for always being willing to quote |
| When you pay it | On entry; a new position shows a small loss immediately, before price has moved at all |
| Tightest conditions | Deep liquidity, active session, no scheduled news |
| Widest conditions | Rollover, news releases, session ends, holidays, market stress |
| What it destroys | Short-target strategies. The smaller your target, the larger a share the spread takes |
What it is and why it works
A chart draws one line, but a market quotes two prices. The bid is the best price anyone is currently prepared to buy from you at. The ask is the lowest price anyone is currently prepared to sell to you at. You always trade on the wrong side of both: you buy at the higher number and sell at the lower one. The difference is the spread.
This is why a fresh position shows a small loss the instant it opens. Nothing has gone wrong. You bought at the ask, and the platform is now valuing your position at the bid, so you are down by the spread. To break even, price has to travel the width of the spread in your favour before you have made a penny.
The spread is not arbitrary and it is not a trick. It is payment for a real service. Someone has to be willing to trade with you at any moment you decide you want to trade, and that someone takes on genuine risk by doing so; they end up holding a position they did not seek, at a moment they did not choose, possibly against a trader who knows something they do not. The spread compensates them for that risk. When the risk rises, the compensation rises with it, which is exactly why spreads widen around news.
How the spread reaches you depends on your broker’s pricing model. Some show a raw institutional spread and charge a separate commission. Others fold their fee into a marked-up spread and advertise zero commission. Neither is inherently better or worse, what matters is the total cost per round trip, which is the only number worth comparing. A third model quotes a fixed spread that does not vary, which sounds attractive until you realise the broker has priced its own risk into that fixed number, and reserves the right to widen it when conditions demand.
How to trade it, step by step
- Find the real total cost of a round trip on your instrument. Add the typical spread to any commission, converted into the same unit, and double nothing, commission is usually charged both in and out, so include both sides. Use the spread cost calculator to turn it into a cash figure for your lot size.
- Express that cost as a percentage of your average target. If your typical target is twenty pips and your all-in cost is two, you are giving away ten per cent of every winner before you begin. If your target is a hundred, the same cost is trivial. If you are unsure how many pips a spread represents on your pair, start with how currency pairs are quoted. This single ratio tells you whether your strategy and your instrument are compatible.
- Watch the live spread for a full day on the instrument you trade. Note what it does at your entry times, at the daily rollover, and around scheduled releases. Most traders have never actually looked, and are astonished at how much it moves.
- Add the spread to your stop distance, not just your target. On a long position your stop triggers off the bid, so a widening spread can reach your stop while the mid price has not. Leave room for that, especially on instruments that widen sharply.
- Refuse to enter when the spread is abnormal. Set yourself a hard threshold (for example, no entries when the spread is more than double its normal level) and honour it. This one rule removes a large fraction of avoidable losses without changing your strategy at all.
- Compare brokers on total cost, not headline spread. A zero-commission account with a marked-up spread and a raw account with commission can cost the same or differ substantially. Work out both on the instrument and size you actually trade. The broker comparison and trading costs guide cover the rest of the fee picture.
- Match your holding period to your cost. If your all-in cost is high relative to the instrument’s daily range, you cannot trade it intraday profitably, but you may be able to swing trade it. Changing timeframe is often a better fix than changing strategy.
- Track cost as a line item in your journal. Record what you paid in spread and commission each month alongside your profit and loss. Traders who do this discover that costs are frequently the difference between a marginally positive and a marginally negative account.
Size every one of those entries with the position size calculator and check the trade is worth taking with the risk/reward calculator before you commit.
The conditions it needs
You know your instrument’s normal range
The spread only means something relative to what the instrument moves. A two-pip spread is negligible on a fast index and punishing on a quiet cross. Judging spread in isolation, without reference to the daily range, is how traders end up on instruments that cannot pay for themselves.
You trade during liquid hours
Spreads are tightest when the most participants are quoting, which for most instruments means the London and New York sessions. The same symbol can cost several times more to trade at 23:00 than at 14:00, and the chart gives you no warning.
Your strategy has room to absorb it
Swing and position traders barely notice the spread; scalpers are dominated by it. If your average winner is only a few multiples of your round-trip cost, execution quality is not a detail of your strategy; it is the strategy.
You are comparing like for like
Total cost per round trip is the only fair comparison between accounts, brokers and instruments. Advertised spreads are typically best-case, measured in ideal conditions, and say nothing about what happens during the hours you actually trade.
When it fails
- “My broker widened the spread to hit my stop.” Spreads widen at the same predictable moments for every client at once, because the underlying liquidity providers widened first. It is a market condition, not a targeted act. The honest concerns about broker conflict are covered in who is on the other side of my trade.
- “Zero commission means cheap.” The fee has usually been moved into the spread rather than removed. Judge accounts on the sum of spread and commission for a full round trip, in cash, on the instrument you trade.
- “Fixed spreads protect me.” A fixed spread is normally wider than a variable one most of the time, because the broker prices in the volatile periods. Most fixed-spread terms also allow widening in abnormal conditions, which is precisely when you wanted the protection.
- Ignoring the spread when backtesting. A strategy tested on mid prices with no costs can look excellent and be unprofitable live. Short-target systems are the worst offenders, because the cost is a large share of the result and gets ignored entirely.
- Setting stops without accounting for the quoted side. Long positions close on the bid, short positions on the ask. A stop placed with no allowance for a widening spread can be taken out by a cost change rather than a price move.
- Chasing the tightest advertised spread and ignoring everything else. Execution quality, slippage behaviour, regulation and withdrawal reliability matter far more than a fraction of a pip. The cheapest quote is worthless at a broker that fills you badly or is difficult to withdraw from.
Where you will see this most clearly
- EUR/USD: The tightest spread in retail forex, and the benchmark everything else gets compared with.
- EUR/GBP: A small daily range makes the spread a large percentage of any realistic target.
- GBP/JPY: Wide spreads and wide ranges together; the ratio matters far more than the raw number.
- NAS100: Spread in index points varies enormously between brokers and across the trading day.
For different levels of experience
If you are brand new
The most confusing moment for a new trader is opening a position and immediately seeing a small red number. Nothing has gone wrong. You bought at the ask and the platform is showing you the bid, so you are down by the spread. Price has to move the width of the spread in your favour just to get you back to zero.
Think of it as an entry fee. It is small, it is unavoidable, and it is completely predictable, which makes it the easiest cost in trading to manage. Two habits handle almost all of it: trade during busy hours, and do not aim for targets so small that the fee eats them.
Be careful of one specific trap. Very tight targets look safe because you are in and out quickly. They are actually the most cost-sensitive trades you can place, because the fee is fixed while the reward shrinks. A ten-pip target with a two-pip cost means you are handing over a fifth of every win.
If your results are inconsistent
If your results hover just below breakeven, run the arithmetic on your costs before you change anything else about your trading. Total round-trip cost multiplied by number of trades per month, compared against your profit and loss, is often a genuinely uncomfortable number, and it explains the gap without any need to question your analysis.
Two fixes usually apply. Trade less, because every trade pays the fee whether it wins or not, and overtrading multiplies a cost you cannot avoid. And take fewer trades in expensive conditions (the last hour of the New York session, the rollover, the minutes around news) where you are paying a premium for worse-quality price action.
Also stop treating the spread as constant when you set stops. A long is stopped out on the bid. If your stop sits three pips below a level and the spread widens by two, you are effectively trading a one-pip stop at that moment. Building a small buffer in for that is not superstition, it is arithmetic.
If you are experienced
The spread is compensation for adverse selection and inventory risk, which is why it correlates so tightly with realised volatility and with the arrival rate of information. It widens ahead of scheduled releases not because anyone is gaming you but because quoting a tight two-sided market into an information event is a losing proposition for the maker.
For anything cost-sensitive the meaningful metrics are effective spread including slippage, fill rate on passive orders, and rejection or last-look behaviour: not the advertised top-of-book number. A venue with a wider quoted spread and reliable fills can be materially cheaper in practice than one advertising near-zero with high rejection rates.
Cost should also be modelled as a regime variable rather than a constant in any systematic work. A strategy whose expectancy survives median conditions but not the upper decile of spread has an edge that disappears in exactly the conditions that generate the tail of the return distribution.
Risk management for this strategy
The spread interacts with risk in a way that catches traders out: your stop is executed on the opposite side of the quote from your entry. A long entered at the ask closes at the bid, so any widening pushes you towards your stop without a single tick of genuine price movement against you.
The practical rule is to build a buffer for the instrument’s realistic worst-case spread into your stop distance, then size the position from that wider stop rather than the tight one. Use the position size calculator with the stop you will actually use. And treat cost as part of the risk-reward calculation, not an afterthought: a setup with two to one reward on paper can be closer to one and a half to one after costs, which changes whether it is worth taking at all.
Where Market Structure Pro fits
Spread is one of the few trading costs you can see coming, and it is also one of the easiest to forget in the moment a setup appears. A chart pattern looks identical whether the spread behind it is normal or triple its usual width.
Market Structure Pro is spread-aware by design. Live spread conditions are an input to the verdict, so a setup that appears while the market is quoting badly is graded for the conditions it is actually in rather than being presented as though it arrived in a perfect market. Combined with its session awareness, that removes the two most common causes of paying far more than you intended to enter a trade.
The verdict itself is a single TRADE, TRANSITION or NO TRADE call with a confidence percentage, an A/B/C grade and a plain-English reason. When cost is what is holding a setup back, the explanation says so, which is more useful than an indicator that fires regardless of whether the trade can pay for itself. MSP is decision support and does not place trades.
One verdict with a confidence score, an A/B/C grade and a plain-English reason. Non-repainting, on every MT5 instrument and timeframe.
Stop guessing whether the setup is valid
Market Structure Pro reads structure, trend, momentum, levels, volatility, volume and session in one pass and gives you a single answer with the reasoning attached. Free 7-day trial, no card required.
Start free trialFrequently asked questions
What is the bid-ask spread?
It is the difference between the highest price a buyer will currently pay, the bid, and the lowest price a seller will currently accept, the ask. You sell at the bid and buy at the ask, so you always trade on the less favourable side of the quote. The gap is the cost of trading immediately.
Why does my trade start at a loss?
Because you buy at the ask and your position is valued at the bid, or vice versa. The small immediate loss you see is the spread, not a mistake or a broker trick. Price must move the width of the spread in your favour before the position reaches breakeven.
Why do spreads widen during news?
Because the people quoting prices face a much higher risk of being traded against by someone reacting faster or knowing more. They widen or withdraw quotes to protect themselves. This happens to all clients at once and reflects conditions in the underlying market, not a decision aimed at you.
Is a raw spread account with commission cheaper?
Sometimes, but you must compare total cost per round trip rather than headline spread. A raw account charges a smaller spread plus a separate commission both in and out; a standard account folds the fee into a wider spread. Work out both in cash for your usual lot size before choosing.
How much does the spread cost me per trade?
Multiply the spread by the value of one pip or point at your position size, and add any commission for both opening and closing. On a standard lot of a dollar-quoted forex pair, one pip is roughly ten dollars, so a one-pip spread costs about ten dollars on entry. A spread cost calculator gives you the exact figure.
Does the spread matter for swing trading?
Far less than for scalping. If you are targeting several hundred pips, a couple of pips of cost is negligible. If you are targeting ten, it can consume a fifth of the trade. The relevant measure is always cost as a percentage of your typical target.
What is a normal spread on EUR/USD?
It is typically the tightest in retail forex, often a fraction of a pip on raw accounts during active hours, with commission added on top. What matters more than the headline figure is what it does at the times you trade, since it widens at the rollover, around news and in thin sessions.
Can the spread trigger my stop loss?
Yes. A long position is closed on the bid, so if the spread widens the bid falls even when the mid price has not moved. A stop placed with no allowance for that can be hit by a change in the cost of trading rather than by a genuine move in price.
Related reading
- What Is Liquidity: The spread is the price of liquidity, understand one and the other makes sense.
- Market Makers Explained: Who receives the spread, and what they are being paid to take on.
- Order Book and Market Depth: The spread is just the gap at the top of the book, here is the rest of it.
- Understanding Trading Costs: Spread, commission, swap and slippage together: the full cost picture.
- Spread Cost Calculator: Turn a spread in pips into the cash it actually costs you at your size.