Bitcoin Order Before the Fed Decision: What Slippage Really Costs You

When you buy Bitcoin with a market order, you rarely pay exactly the price the app showed you beforehand. The difference is called slippage, and it does not come from a fee but from the depth of the order book: your order works its way up through the sell offers on hand until it is filled. How expensive that gets depends on how much capital sits right next to the current price.

We measured this ourselves across five exchanges on September 14, 2026, in three time windows between 15:51 and 15:53 UTC. The headline result: for a purchase of 100,000 euros the markup in the third window ranged from 10.50 euros to 329.86 euros, depending on which exchange you pick. That is a factor of 31 for exactly the same action in the same minute.

This analysis was compiled by cryptoticker.io on September 14, 2026.

Slippage on a Bitcoin order: what the term means precisely

Slippage is the gap between the price you see when you submit the order and the average price at which it is actually executed. It is not a fee and never appears on a statement as its own line item. It sits inside the execution price.

The mechanism behind it is an order book. An order book is the price-sorted list of all open buy and sell orders on an exchange. On the sell side the cheapest offer sits at the top, with more expensive ones below. A market order takes those offers in turn until your amount is used up. If only a few Bitcoin sit just above the current price, your order reaches higher price steps quickly.

The first cost block here is the spread. The spread is the distance between the highest bid and the lowest ask. Even a tiny market order pays half the spread arithmetically, because it starts at the midpoint and executes at the upper end. On large orders the depth effect comes on top.

The distinction matters in practice. A trading fee of 0.25 percent is known to you in advance and you can look it up in a crypto exchange comparison. Slippage is written down nowhere, because it depends on the state of the book in the exact moment you tap buy.

Our own measurement: how deep the euro order books of the five exchanges really are

We queried the public order book interfaces of Kraken, Coinbase Exchange, Bitstamp, Bitvavo and Bitfinex, each for the Bitcoin against euro pair. From each book we formed the mid price, calculated the spread and then simulated how a market order of 1,000, 5,000, 25,000 and 100,000 euros eats its way through the sell side.

We measure depth as the sum of the capital sitting within half a percent of the mid price in the book. That figure says more about an exchange's resilience than trading volume does, because volume also arises from thousands of small orders that consume each other.

For Bitcoin against euro the picture across the three windows was as follows:

• Kraken: spread 0.0001 to 0.0041 percent, depth 12.98 to 13.97 million euros
• Coinbase Exchange: spread 0.0079 to 0.0195 percent, depth 5.66 to 6.09 million euros
• Bitstamp: spread 0.0006 to 0.0220 percent, depth 2.48 to 2.60 million euros
• Bitvavo: spread 0.0015 percent, depth 2.23 to 2.42 million euros
• Bitfinex: spread 0.3707 to 0.4590 percent, depth 0.58 to 0.84 million euros

Between the deepest and the shallowest euro book in our sample there is therefore roughly twenty times as much immediately available capital. The Bitcoin price itself stood at around 68,100 euros at the time of measurement, which is about 78,620 US dollars.

What the numbers mean for a concrete order

Converting the percentages of the third window into euros makes the difference tangible. A market purchase of 100,000 euros cost 10.50 euros in slippage at Bitvavo, 16.25 euros at Bitstamp, 19.15 euros at Kraken, 45.89 euros at Coinbase Exchange and 329.86 euros at Bitfinex.

On small amounts the picture partly reverses, because there the spread alone counts. An order of 1,000 euros cost around one cent at Bitvavo, six cents at Coinbase Exchange, eight cents at Kraken, eleven cents at Bitstamp and 2.02 euros at Bitfinex. Anyone trading small sums notices little of the depth problem. Anyone buying in four figures and up notices it immediately.

Market order or limit order: which order type caps the slippage

A market order is executed immediately, at whatever price the book provides. A limit order sets a maximum price and is only executed if the book offers that price. The difference between the two is precisely the quantity we measured.

In practice that means: set a buy limit at 68,150 euros while the price stands at 68,100 euros, and no execution above that value can happen to you. If the depth is not there, part of the order stays open instead of being filled expensively. You can leave that remainder standing or cancel it.

The price for this is uncertainty. A limit order can sit unfilled while the price runs away. In a calm market that is no problem. In the minutes around a central bank decision an unfilled order can mean you miss a move. Nobody can make that trade-off for you, but you should make it deliberately rather than reaching for the market order out of habit.

Euro against dollar: why the same Bitcoin order book is shallower in euros

The clearest finding of our measurement cuts across the exchanges: it concerns the currency of the trading pair. We additionally queried the Bitcoin against US dollar pair at the same providers. In the third window the depth within half a percent stood at 13.97 million euros at Kraken against 34.39 million dollars, at Bitstamp at 2.60 against 11.25 million, at Coinbase Exchange at 6.09 against 38.11 million and at Bitfinex at 0.58 against 10.24 million.

That works out at factors of 2.5 at Kraken, 4.3 at Bitstamp, 6.3 at Coinbase Exchange and 17.5 at Bitfinex. The dollar market is the main market at all four houses, the euro market a sideshow. This describes a property of European crypto trading as a whole and not a weakness of any single provider.

Bitfinex is the most instructive case here. The same exchange showed a spread of between 0.0089 and 0.0140 percent in the Bitcoin dollar book and between 0.3707 and 0.4590 percent in the euro book. The provider's technology does not explain that gap. What decides it is where market participants place their capital.

For you this carries an immediate consequence: the detour via a dollar or stablecoin pair can be cheaper than the direct euro purchase as soon as the order size noticeably strains the euro depth. Set against that, though, are the conversion costs and a possible second trading fee. We already counted how strongly euro pairs feature in an exchange's listings at Coinbase Exchange back in August 2026: at the time, 34 of 399 tradable assets there had a euro order book.

Spread, fee and slippage: which cost block dominates on small orders

Many investors optimise the trading fee and overlook the other two items. Our numbers show that this order of priority is usually right for small orders and no longer right for large ones.

On a purchase of 1,000 euros the slippage costs came to under twelve cents at four of the five exchanges measured. A trading fee of 0.25 percent would have amounted to 2.50 euros on the same order, twenty times as much. Anyone buying small and rarely does well to look at the fee schedule first.

From around 25,000 euros the relationship shifts. There the slippage reached 0.0346 percent at Coinbase Exchange and 0.2630 percent at Bitfinex, while at Bitvavo it stayed at 0.0013 percent in the third window. On six-figure amounts the depth difference can swallow a lower fee entirely.

Brokers without an order book: what Bitpanda, BISON and Trade Republic do differently

Some of the providers popular in Germany do not work with an open order book at all. There you buy against the provider itself, which quotes you a price. That is convenient and carries one drawback our method makes visible: there is nothing to measure.

Bitpanda's public price interface gave us a single Bitcoin price of 68,092.99 euros on the day of measurement, with no bid and ask side and no depth figure. How much markup sits in the actual purchase price cannot be checked from outside. At Coinbase the gap is at least visible: the retail interface quoted a buy price of 68,122.48 euros and a sell price of 68,093.28 euros at the same moment. Between the two lie 29.20 euros, or 0.0429 percent, and that is before any fee.

This is no reproach to the business model. A broker takes on the execution risk and charges for it. You should simply know that with a broker you cannot recalculate the price of that convenience, whereas on an exchange with an open book it is verifiable down to the decimal place. Anyone torn between the two worlds will find the differences broken down in the crypto broker comparison.

Checking order book depth yourself: how to look into the book before you buy

You need no software for this. Every exchange with an open order book displays it in the trading view, usually next to the chart and often collapsed.

Three steps are enough. First: look at the distance between the top bid and the top ask. If it is above 0.1 percent, the book is already conspicuously thin for a major asset like Bitcoin. Second: roughly add up the amounts in the first ten to twenty sell rows. If your planned order size is larger than that sum, you will be executed across several price steps. Third: compare the same view in the dollar or stablecoin pair of the same asset.

If you need more precision, you can query the interfaces yourself. Kraken documents retrieving the order book in its public API reference, and Bitfinex describes the same procedure for its book. Neither call needs an account or a key.

Ethereum order books compared: where the depth thins out further

We ran the same measurement for Ethereum against euro. The price stood at around 2,172 euros, and the pattern repeats in sharper form.

Kraken came in at a depth of 9.35 to 9.56 million euros, Coinbase Exchange at 1.46 to 1.59 million, Bitvavo at 1.18 to 1.37 million, Bitstamp at 0.86 to 0.91 million and Bitfinex at 0.44 to 0.49 million. A market purchase of 100,000 euros therefore cost between 0.0095 percent at Kraken and 0.4221 percent at Bitfinex.

At Bitstamp the euro depth fell by roughly two thirds from Bitcoin to Ethereum, and at Coinbase Exchange by about three quarters. The further you move away from Bitcoin, the more the choice of exchange weighs. For smaller altcoins in euro pairs you should expect considerably thinner books, even though we did not measure that in this survey.

Thin liquidity ahead of the Fed decision: what that means for your order

Our measurement fell in an unusual week. The US central bank decides on the policy rate on September 16, 2026, and market reports from the day of measurement consistently describe liquidity tightening in the run-up. According to reports by finanzen.net and wallstreet-online, citing the CME Group's FedWatch tool, a rate hike was most recently priced in with a probability of around 86.5 percent, after the producer price index for August rose by 5.4 percent.

Whether the books were thinner for that reason than on an ordinary Monday afternoon is something three time windows on a single day cannot establish. We lack the comparison figure from a quiet week, and so we do not claim it. What can be said: the differences between the exchanges were stable across all three windows, and the ranking stayed unchanged.

For the days around a central bank decision one principle holds anyway, independently of our numbers. In phases of high expectation many market participants pull their offers out of the book, because they do not want to be filled at a stale price. In exactly the moment when the price moves fastest, the least capital is there to absorb orders.

Limits of this measurement: what three time windows do not show

We are open about what this survey does not deliver. It is a snapshot of 42 order book retrievals on one afternoon, analysed across 217,454 individual order book rows. It shows the order of magnitude of the differences, not a daily, weekly or monthly average.

Three further limitations belong with it. First, we measured Bitfinex in the first two windows at a different retrieval depth before switching to the maximum row count. The spread values are untouched by that, and at this exchange they are the dominant cost factor. Second, we simulate execution against a standing book. In reality other participants react to a large order, which can turn out both cheaper and more expensive. Third, we calculated the buy side only; the same mechanisms apply to sales, but not necessarily the same numbers.

We were also unable to check what share of the offers in the books comes from automated trading programs. That cannot be separated out from public order book data, and we draw no conclusions from it either.

Checking slippage on Bitcoin orders: what to take away

1. Compare order book depth before you buy, not just the fee. On amounts from around 25,000 euros it was depth rather than the fee schedule that decided total costs in our measurement. Which houses come into question for euro trading at all is set out in the crypto exchange comparison.
2. Use a limit order rather than a market order for larger purchases. A limit set close above the current price costs you a delayed execution in the worst case, but protects you from slipping across several price steps. Anyone who would rather buy against a fixed price should weigh the markup in the crypto broker comparison.
3. Check whether your provider shows the book at all. Without an open order book you cannot recalculate the markup in the purchase price. If that verifiability matters to you, watch for it when choosing and factor in the provider's supervision, for instance via the overview of regulated crypto exchanges.

(As of September 14, 2026. This article is not investment advice. Prices and fee structures change; check the terms with the provider before you buy.)