The previous article ended on a question: a coin’s price is whatever the next buyer pays — but where do buyer and seller meet? On an exchange. This article is about the machinery there, because it decides three things: what a price is, what you actually own after buying, and what the data on this site actually is.
A centralized exchange is a queue of offers
Strip away the charts and a centralized exchange is a list called the order book: everyone who wants to buy, with the price they will pay, and everyone who wants to sell, with the price they will accept.
Nothing happens until two of those offers overlap. When the highest bid meets the lowest ask, a trade prints — and that print is the price you see on a chart. A price is not a fact about a coin. It is a record of the last time two people agreed, on one venue.
That qualifier matters. Not every venue works this way: decentralized exchanges built on automated market makers have no order book at all — they price trades from a pool by formula. This article is about the order-book kind, which is where nearly all price history comes from.
Two consequences to carry forward:
- There is no single price. Different venues have different books, so the same coin trades at slightly different prices in different places at the same moment.
- The chart is history, not availability. The last print says what someone paid, not that you can buy at that number now.
Buying on an exchange usually means the exchange holds your coin
The previous article split ownership two ways: you hold the key, or somebody holds it for you. Buying on a centralized exchange is the second case by default. The exchange records that you own a balance in its own database; the ledger entry sits under the exchange’s key.
That is not a warning, it is a description of what you bought: a claim on a company that has promised to give you the coin when you ask. Whether you move it to your own key afterwards is a separate decision, with a separate set of risks in each direction.
Maker and taker: how your order met the book
Exchanges define this precisely. An order gets the maker fee “if the trade order is not matched immediately with an opposing order already on the order book,” and the taker fee “if the trade order is matched immediately against an order already on the order book” (Kraken — What are Maker and Taker fees?).
In plain terms: you either place an offer and wait (your order sits on the book for someone else to trade against) or you take an existing offer (your order matches something already sitting there).
Whether the two are priced differently is a per-venue fact, not a rule. Of the two exchanges we track, both charge a lower maker rate on futures — but on spot, one of them charges the same either way. So “wait on the book and pay less” is something to check on the venue you are using, not to assume. Our fee comparison keeps the current rates for both.
There is also a cost with no fee attached: the spread, the gap between the best bid and the best ask. Cross it to get filled immediately and you give up roughly half that gap against the midpoint on entry — and the other half when you eventually close.
Fees and spread together are the real cost of a trade, and they get their own article: Crypto Trading Fees Explained has the per-exchange numbers, and Order Types & Execution Strategies covers how to choose an order so you pay less of it.
Spot and perpetuals are different products on the same screen
The same exchange usually offers two things side by side. Spot is buying the coin itself. Perpetual futures are a contract that tracks the price without ever expiring — you never hold the coin, and a periodic funding payment keeps the contract near the spot price.
This distinction is not academic here: the price history on this site is perpetual-swap data — Binance for the historical stretch, OKX USDT-SWAP for the live one. So when a backtest here says a strategy returned some number, it is a claim about a perpetual contract on one venue’s book, not about buying and holding the coin.
What you actually do on that screen — place an order, hold a position, close it — is the next article in this track. The leverage and liquidation mechanics of the perpetual product come after it.
What you should be able to say now
- A centralized exchange is an order book, and price is the record of the most recent match on it.
- Buying there normally means the exchange holds the coin; your own key is a separate step.
- Maker and taker describe how your order met the book; whether they cost differently is a per-venue fact.
- The spread is a cost even when no fee is charged.
- Spot and perpetuals are different products — and this site’s data is the perpetual kind.