The price you click is a request, not a result. Between your click and your trade sit routing, liquidity, and time — and in that gap live slippage, requotes, and the most important small print in trading: a stop-loss is an instruction, not a guarantee. This sheet explains what actually happens to an order, and how to audit your own fills.
The lifecycle of an order: click, route, fill
When you press buy, three things happen in sequence. Your platform sends the order to the broker; the broker routes it — to its own dealing system, to liquidity providers, or both; and an execution comes back: a fill, stamped with the price and time at which the trade actually happened. On a calm day in a major pair this takes milliseconds, and the fill matches the quote you saw.
But the quote on your screen was already history when you clicked it — a snapshot of a price that updates many times per second. The market does not pause while your order travels. Whatever the price is when your order arrives is the price you deal at. Most of the time the difference is zero. The rest of this sheet is about the times it is not.
Order type decides how that risk is shared. A market order accepts whatever price is available — certain to fill, uncertain in price. A limit order reverses the deal: it can only ever fill at your price or better, so it cannot slip against you, but in a fast market it may simply not fill at all, leaving you without the position — or still inside one you wanted out of. There is no order type that is both certain to fill and certain in price; everything that follows is the working-out of that trade-off.
Slippage: why it exists, and that it cuts both ways
Slippage is the difference between the price you requested and the price you received. Suppose you buy one standard lot of EUR/USD at a quoted 1.0850. If the order fills at 1.0852, you slipped 2 pips against you — $20 on the spot, at $10 per pip. If it fills at 1.0848, you slipped 2 pips in your favor — $20 better. Both happen. An execution process that is working honestly produces slippage in both directions, because price movement during transit is random with respect to your order.
Three conditions make slippage larger. News: in the seconds around a major release, prices jump in steps rather than ticks, and the price your order meets can be many pips from the one you clicked. Thin liquidity: at rollover, at the Friday close, and in holiday sessions, fewer quotes are available, so the next available price is further away. Size: a large order can consume everything offered at the best price and fill the remainder at worse ones.
One diagnostic is worth remembering: symmetry. Over many trades, favorable and unfavorable slippage should both appear in your records. If every recorded slip on your statement goes against you and none ever go your way, that is not bad luck — it is a question to put to your broker, in writing.
Gaps: when price skips your level entirely
A gap is a jump between one traded price and the next, with no trades in between. The market does not move through the skipped prices — they simply never exist. Gaps appear at the weekend open, when two days of news meet the first quote of the week, and mid-week around major scheduled events such as central-bank decisions.
Work one example. You are long one standard lot of EUR/USD from 1.0850 with a stop-loss at 1.0800 — planned risk of 50 pips, or $500. Over the weekend, news breaks. The market opens Sunday at 1.0762: 38 pips below your stop. Your stop triggers on the first available price and fills near 1.0762. Actual loss: 88 pips, $880 — 76% more than planned. Nothing malfunctioned. There was no price between 1.0800 and 1.0762 to exit at, because no trades happened there.
The same mechanics can pay you. If you held a take-profit at 1.0900 and the market gapped open at 1.0915, a fair execution fills you at the better price — $150 more than planned. Gaps are not a fee charged by someone; they are the market teleporting. The lesson is not to fear them but to budget for them: any position held over a weekend or through a major release carries gap risk that no order type removes.
Gap risk is also the one execution risk you can decline entirely. A position closed before the Friday close cannot meet Sunday's opening print, and a trader who is flat through a rate decision cannot be gapped by it. Holding through those windows is often a reasonable choice — but it should be a priced choice, made in advance, not an ambush discovered on the statement.
The stop-loss small print: protection at the next available price
A stop-loss is a pre-placed instruction: when price touches my level, send a market order. That last phrase is the small print. Once triggered, your stop is an ordinary market order, and it fills at whatever price is actually available — which in fast or gapping markets is worse than the trigger. The stop limits how long you stay wrong; it does not put a floor under a single trade's loss.
Some brokers offer guaranteed stops on some instruments, for a premium charged whether or not the guarantee is used. That is an insurance product with a price, not a flaw in ordinary stops. The practical defence costs nothing: size positions so that a stop slipping well past its level — double the planned distance, say — is unpleasant rather than fatal. A stop placed 50 pips away is a plan; the position size is what decides whether a 90-pip exit is survivable.
The same mechanics, in the formal language we are accountable for.
Requotes and rejections: what they signal
A requote is the broker declining your requested price and offering a new one: the price moved, take it or leave it. A rejection is the order simply failing. Both are common around news and in thin hours, and occasional ones are the honest cost of asking for a price that no longer exists.
Their frequency, though, is a measurement of your broker. Frequent requotes in calm markets suggest the quoted price was never firmly available. Persistent one-directional behavior — requotes only when the move would have favored you — deserves the same written question as one-directional slippage. Keep a note of when they happen; patterns are evidence, single events are weather.
How to audit your own fills
One honest caveat before you start measuring: demo fills are simulated. A demo platform mirrors live prices, but your orders consume no real liquidity there, so demo execution is usually kinder than the live version — fewer slips, no requotes, instant fills at size. The demo is the right place to learn how order types behave; it is the wrong place to judge a broker's execution quality. Only live fills count as evidence.
Everything this sheet describes is recorded in your account statement, which makes it checkable. The method: export your recent orders, and for each one compare the requested price with the executed price. Count three buckets — filled better, filled exactly, filled worse — and note where the worst slips happened against the clock and the calendar.
Healthy execution over twenty or more orders looks like this: most fills exact, slips small and in both directions, the largest ones clustered around news or thin hours. What you are looking for is the absence of a pattern that always favors the other side. Ten minutes with your own data answers questions that no review site can.
Place stops and limits around a scheduled release with stage money, and watch how fills behave when it is free to learn.