Spread and Slippage: The Costs That Aren't on the Fee Page
The spread is the gap between the price you can buy at and the price you can sell at in the same moment, and slippage is the difference between the price you were shown and the price your order actually filled at, and neither one appears as a line item on your trade confirmation.
Updated · By RampAtlas Research
Key takeaways
- The spread is the gap between the buy price and the sell price at the same moment, and it is charged on every round trip.
- Slippage is the difference between the price you were shown and the price your order filled at, caused by order book depth rather than by a fee.
- As of September 2026, Kraken states that spreads and card processing fees still apply when Kraken+ waives trading fees (source: Kraken fee schedule).
- Zero-commission platforms are not free, because the margin sits in the quoted price instead of a commission line.
- RampAtlas includes an estimated spread in its cost figures where an exchange publishes one, and shows a dash rather than a guess where it does not.
In this guide
The spread is the gap between the price you can buy at and the price you can sell at in the same moment, and slippage is the difference between the price you were shown and the price your order actually filled at, and neither one appears as a line item on your trade confirmation.
Both are real money. On a small purchase of a thinly traded asset they can exceed the trading fee that the entire comparison industry focuses on.
| Spread | Slippage | |
|---|---|---|
| What it is | The gap between the best bid and the best ask at one instant | The difference between the price you were shown and the price your order filled at |
| Who collects it | Whoever is on the other side of your trade | Nobody. It is the arithmetic of buying more than is available at one price |
| When you pay it | On every round trip, buying at the ask and selling at the bid | When your order is bigger than the price level it fills against |
| What drives it | Liquidity, volatility, and the venue's quoting model | Order size relative to depth, market speed, and the venue |
The spread
At any instant an order book has a best bid, the most a buyer will pay, and a best ask, the least a seller will accept. The spread is the distance between them.
You buy at the ask and sell at the bid, so buying and selling immediately leaves you down by the spread even if nothing about the market changed. That makes it a genuine transaction cost. It is simply collected by the market rather than billed by the exchange.
Express it as a percentage before comparing anything. A six-dollar spread on a sixty-thousand-dollar asset is 0.01% and irrelevant. A six-dollar spread on a three-hundred-dollar asset is 2% and dominates every other cost in the trade.
What makes a spread wide
Three factors, and they compound.
| Factor | How it works |
|---|---|
| liquidity | A pair with many active participants has orders stacked close together, and a pair with few has gaps. The same asset can have a tight spread on a large exchange and a wide one on a small exchange, because the spread describes the venue and the pair rather than the asset in the abstract. |
| volatility | Market makers widen quotes when prices move fast, because the risk of being caught on the wrong side rises. Spreads that are invisible on a quiet afternoon become noticeable during a sharp move. |
| Quoting model | A broker that shows you one price rather than a book is not passing you the market's spread. It is setting its own, and it can set it wherever it likes. |
Why zero commission is not free
An advertised zero-commission platform still has to make money. When there is no commission line, the margin is in the quote: you are shown a buy price a little above the market and a sell price a little below it, and the difference is revenue.
Few people do that, which is why the model persists.
Kraken's own fee schedule makes the separation explicit. As of September 2026, the schedule states that Kraken+ subscribers have trading fees waived on up to $10,000 of monthly volume while spreads and card processing fees still apply (source: Kraken fee schedule).
A cost estimate for a $500 purchase on Kraken, Coinbase Exchange, Gemini and Binance US appears here once the published fee schedules are verified.
Slippage
slippage is what happens when your order is bigger than the price level it is filling against.
An order book lists a quantity at each price. If the best ask holds less than you are buying, your market order takes all of it, then moves to the next level, then the next, until it is filled. The average price you pay is a blend of every level it touched, and it is worse than the price you were quoted.
Three things drive it. Order size relative to depth, which is the whole mechanism. Market speed, since the book can change between the moment you press buy and the moment your order arrives. And the venue, because a smaller exchange has thinner levels for the same pair.
Slippage is not a fee, and no exchange charges it. It is the arithmetic of buying more than is available at one price.
How to reduce both
Four practical measures, in rough order of usefulness.
- Use the trading interface rather than the simple buy button. The book price with a stated taker fee is almost always cheaper than a single quoted price with the margin hidden inside it.
- Place a limit order instead of a market order. A limit order caps the price you can be filled at, which converts slippage from an unknown into a boundary you set. Where the order rests on the book rather than crossing it, you also earn the cheaper maker rate. The trade-off is covered in Limit vs market orders.
- Split large orders. If your size exceeds the first few levels, breaking it into pieces over minutes lets the book refill between them.
- Check the spread before you buy, especially on assets outside the largest few. Reading the book takes seconds once you know what the columns mean, which is covered in How to read an order book.
How RampAtlas treats these costs
Our cost estimate for a purchase adds three components from each exchange's published information: the taker trading fee, an estimated spread where the exchange publishes one, and the deposit fee for the cheapest widely available payment method. Network withdrawal fees, promotional discounts, and volume-tier discounts are excluded unless stated.
Where an exchange does not publish enough to estimate one of those components, the cost renders as a dash rather than a number, and that exchange cannot be ranked as the cheapest option. Guessing a spread would make the ranking look complete and be wrong. The full rule, including how cost is weighted in the overall exchange score, is on Methodology.
Where to compare
Costs are only comparable within a jurisdiction, because the set of available exchanges differs. Start at Buy Bitcoin or Buy Ethereum for a ranked list with an estimate against each exchange, and use Compare to see two venues across $100, $1,000, and $10,000, since the ranking changes with size. Exchange pages carry each operator's own fee explainer, including Kraken, Coinbase, and Bitstamp by Robinhood. Asset background sits on Ethereum.
Frequently Asked Questions
Is the spread a fee?
Not in the sense that anyone bills you for it, and yes in the sense that it costs you money on every round trip. It is the difference between what you pay to buy and what you receive to sell at the same instant, and it is collected by whoever is on the other side of your trade.
How do I find out what spread I am being charged?
On an exchange with a book, read the best bid and best ask and take the difference as a percentage of the price. On a platform that quotes a single price, request a buy quote and a sell quote for the same amount at the same moment, and compare them.
What is an acceptable amount of slippage?
That depends entirely on your size against the depth available, so there is no universal figure. The useful test is whether the quantity you want sits inside the first few levels of the book. If it does not, either use a limit order or split the order.
Why do the same coins cost different amounts on different exchanges?
Trading fees differ, and depth differs more. A venue with a thinner book for that pair produces a wider spread and more slippage at the same order size, which shows up as a worse fill even when the advertised fee is identical.
Does RampAtlas include the spread in its fee estimates?
Yes, where the exchange publishes enough to estimate it. Where it does not, we show a dash instead of a number and exclude that exchange from cheapest-option claims, as described on our methodology page.