Your fee was $75. Slippage cost another $980.

You size a position at $100,000. You tap market. The fill comes back at an average price worse than the one on your screen.

The fee on that order is $75. The gap between the quote and the fill is more.

Nobody put it on a fee page, because it is not a fee.

It is the book telling you what it had.

Every guide about trading cost stops at the fee schedule. The fee schedule is the easy part: it is published, it is a percentage, and you can multiply it. The number that actually decides whether a scalp is profitable is the one that is not published at all — how much the price moves against you between deciding and filling.

Two costs, one click

A market order does not execute at one price. It executes against every resting order it can reach, best price first, until your size is filled. You get a volume-weighted average. The further your order reaches down the book, the worse that average gets.

The taker fee is charged on the whole notional regardless. Slippage is charged by the book, and it scales with size, not with the fee schedule.

Why size changes the answer more than the rate does

On the contract measured here, the taker rate is 0.0750%. On $100,000 that is $75.00 to enter. You can compute that from the fee page without opening an account.

What you cannot compute from the fee page is how much depth sits in the top few levels right now. A book with $900,000.00 resting in the first three levels absorbs your order with almost no price impact. A book with $60,000.00 does not.

Read the last column again. On a thin book, the cost you cannot see is more than six times the cost you budgeted for.

The counter-intuitive part: your fee is not your biggest cost

Traders optimise what they can see. They chase a lower taker rate, they switch to limit orders to earn the rebate, they compare exchanges on the schedule. All of that is worth $170.00 per round trip on $100,000 — a real number, and the subject of most of this site.

Slippage on a thin book can be $980.00 on one side of the same trade. The optimisation that takes ten seconds of attention (checking depth before you hit market) can be worth more than the one that takes an afternoon of reading fee tables.

Measure yours in two minutes

1. Open your last ten market orders. Not the P&L summary — the fills.
2. For each, take the average fill price and the mark price at the moment you clicked. Most platforms show both on the order detail.
3. Multiply the gap by the notional. That is what the book charged you. It is not in any fee field.
4. Compare that total to the fees on the same ten orders. On most accounts one of these is far bigger than the other, and it is rarely the one people expect.

If slippage is the larger number, the fix is not a different exchange. It is a limit order at the quote, or splitting the order, or trading when the book is deeper. None of those cost anything to try.