The fill you actually get
Slippage, requotes, and a test you can run yourself
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The price is a promise about the market. The fill is what you actually got. The gap between them is measurable, it is the most honest number about any broker — and you can collect it yourself in a fortnight.
AI Mentor here. 🧠 Everything so far has been about how the machine works. This lesson is the one you can act on today, because it is the only part of a broker you can measure from the outside.
What slippage actually is
Slippage is the gap between the price you saw and the price you got. It happens because the two are separated by time — a few milliseconds in which the market can move and the quote you clicked can stop being available.
The first thing to get straight is that slippage is not inherently against you. A market that moves in your favour in those milliseconds fills you better than you asked for. That is positive slippage, it is real, and whether you ever see it is the single most revealing thing about a broker.
A firm passing your orders to a real market has no way to make slippage one-sided. If you only ever slip against yourself, something is choosing that.
When it is normal
Some slippage is physics, and calling it a scandal only makes it harder to spot the real thing.
• Around scheduled news. In the seconds after a rate decision the price genuinely gaps. There is no quote in between to fill you at.
• On stop orders. A stop becomes a market order when it triggers. It asks for the next available price, and in a fast move the next available price can be some distance away.
• In thin hours. Fewer providers quoting means less depth, and a normal-sized order can walk through what there is.
• On large size. Your order may be bigger than the best quote available, so part of it fills further away.
When it is not
Set against that, here is what does not have an innocent explanation.
Asymmetry. Slippage that lands against you far more often than for you, in ordinary market conditions, is not a market phenomenon. Real market movement is roughly symmetric over many trades.
Slippage only on stops, never on entries. If your entries fill exactly at the quote but your stops consistently fill worse, the two are being handled differently.
**Requotes in a calm market.** A requote is the broker refusing your price and offering another. It made sense when quotes were delivered slowly; on a modern platform, in a quiet hour, it mostly means the firm did not want that trade at that price.
Everyone gets a shocking fill eventually, usually around news, usually on a stop. A single example is a story. Twenty logged fills are evidence. Do not change broker over the first; do not ignore the twentieth.
The test you can run yourself
This is the part worth actually doing, and it costs almost nothing.
Trade your smallest possible size — micro or nano — for two weeks, and for every order record four things: the price shown when you clicked, the price you were filled at, the time, and whether anything was scheduled.
Then count. How many fills were better than shown, how many worse, and how many exact? In normal conditions a genuinely passed-through broker produces a spread of all three, roughly balanced between better and worse.
Twenty micro-lot trades cost a few euros in spread and buy you the only fact about your broker that nobody else can hand you. No review site can run this test on your account, at your hours, on your pairs.
What the firm publishes
Brokers are not silent on this — most simply hope nobody reads it.
The order execution policy states how orders are handled, what the firm treats as best execution, and whether price improvement is passed to you. Many firms also publish execution statistics: fill rates, average slippage, rejection rates. Some publish a median execution time.
Read the policy first, then run the test. A firm whose document promises symmetric price improvement and whose fills are consistently one-sided has told you something about itself that no review can.
Next we leave the CFD world entirely and look at the other family of brokers — the ones where trading appears to be free.
See you on the desk. — AI Mentor