Why one coin's price differs across exchanges, and when the gap is real

The Gap column on the site's index is how far apart the cheapest and the dearest exchange are for each coin, in basis points: 1 bp is 0.01%. On Bitcoin it's usually a few. On a thinly traded coin it can be a hundred or more. This is where it comes from, and how to tell a gap worth acting on from one that isn't really there.

Every exchange is its own market

An exchange's price is set by its own buyers and sellers, in its own order book. Nothing makes two exchanges agree except traders: when a coin is cheaper on one, someone can buy it there and sell it on another, and that pushes the two prices back together. They keep doing it while the gap pays more than it costs them to trade on both and to move coins and money between the exchanges. So gaps never quite close, and where there are plenty of traders they stay small.

Bitcoin: a few basis points

At 13:45 UTC on 2 October, the middle of Bitcoin's order book on ten exchanges spanned $28.71, or 3.3 bps, from Binance's to Coinbase's. On a $10,000 buy, that's about $3.30 between the cheapest exchange and the dearest.

Bitcoin on ten exchanges: basis points above the cheapest

• Binancepriced in USDCcheapest
• Gatepriced in USDT+1.0
• OKXpriced in USDC+1.0
• Bitgetpriced in USDC+1.1
• Bybitpriced in USDC+1.7
• Krakenpriced in USD+2.6
• Bitstamppriced in USD+2.9
• Hyperliquidpriced in USDC+2.9
• Crypto.compriced in USD+3.0
• Coinbasepriced in USD+3.3

The middle of each book in dollars, USDC at $0.99985 and USDT at $0.999795. 13:45 UTC, 2 October 2026.

A dollar isn't always a dollar

Six of those ten price Bitcoin in USDC or USDT, not dollars. Each is meant to be worth a dollar and trades close to it, but not exactly: at 13:45 a USDC was worth $0.99985 and a USDT $0.999795, at Kraken's live rates, which the site uses. Binance's mid of 86,918.87 USDC was $86,905.83. Taken as dollars without converting, it would have looked 1.5 bps dearer than it was, nearly half of Bitcoin's whole gap. So the site converts every stablecoin price at the live rate before it compares anything.

More exchanges, wider gaps

The gap is the cheapest exchange against the dearest, so every exchange you switch on is one more chance of an outlier. At 13:47 UTC, with the four exchanges the site starts with, the middle coin on the spot index had a gap of 12 bps, and 27 of 114 coins were under 5. With ten switched on, a minute earlier, the middle coin's gap was 29 bps and 4 of 116 were under 5.

Coins on the spot index, by the width of their gap

The four on by defaultTen exchanges

• Under 5 bps27 of 1144 of 116
• 5 to 20 bps56 of 11436 of 116
• 20 to 50 bps26 of 11448 of 116
• Over 50 bps5 of 11428 of 116

Buying: each exchange’s ask in dollars against the lowest. The middle coin’s gap was 12 bps with the four and 29 with ten. Ten at 13:46 UTC, the four at 13:47, 2 October 2026.

Often a single exchange sets a wide gap on its own: a smaller market, with fewer orders in its book, quoting a price further from the rest.

When the gap is real

The gap on the index is a real saving for a small order, as it stands: each exchange's price there is its best ask, or its best bid when you choose Selling, which is where a market order starts. For a buyer choosing where to buy, it's what choosing well is worth. Some things make it smaller than it looks, and the site marks each of them:

• A thin book. If an exchange's best ask is more than 5% above its best bid, the site says Thin and leaves it out of the gap: the middle of a book that wide is a price nobody is trading at.
• A closed market. Some exchanges pause tokenized stocks outside their trading hours. The site says Closed and leaves them out until they reopen.
• A quiet market. Under $100K traded in 24 hours, a drop marks the exchange's cell: its best price may be a few small orders.
• A big order. The best price is only the first level of a book. A bigger order goes deeper, and the cheapest exchange for $1,000 isn't always the cheapest for $1,000,000. The Trade simulator on each coin's page, like Bitcoin's, walks every book for your own amount.

For anyone trying to profit from the gap itself, buying on one exchange and selling on another at once, it has to be wider than both spreads, the cost of trading on both sides and the cost of moving coins and money between them. That's the traders' work in the drawing above, and why on Bitcoin there's rarely much of it left.

Reading it on the index

Under about 5 bps it hardly matters where you trade; over 20, it's worth a look. Each exchange's column says how many basis points it is behind the best, so a gap set by one far-off exchange stands out. Choose Buying or Selling at the top, switch on the exchanges you can use, and the gap is between those. Then open the coin to see its books, its depth and what your own order would cost on each.