Methodology

Where every figure on the site comes from, how it’s compared, and what it can’t tell you.

The counts and rules on this page are filled in from the site’s own code each time it’s built, so they say what the site does today.

Where the data comes from

Every price, order book, trade, funding rate and open interest figure is the exchanges’ own public market data: what their own sites and apps show anyone. Your browser reads it and does every sum itself as it arrives: the gaps, the rankings, the fees, the funding and Signals are all worked out on your screen.

The site reads 28 exchanges. Kraken, Coinbase, OKX and Hyperliquid are on when you first visit; the others are a click away, in the header’s exchange switch. The scoreboards, the exchanges’ own pages and Signals read every exchange of their kind while they’re open, unless you choose “Only exchanges I use”. Each exchange’s page says how the site reads it, and how often.

Market caps are the one figure that isn’t the exchanges’: a coin’s circulating supply from CoinGecko, or a company’s shares outstanding from its latest SEC filing, times the live price, with the day the supply or the shares were read.

What’s compared

  • On the indexes and in the scoreboards’ rankings, each exchange’s price for the side you choose: its ask, the lowest anyone there will sell at, when you’re buying; its bid, the highest anyone will pay, when you’re selling. That’s the price a trade starts at.
  • On a coin’s page, the middle of each order book, halfway between its best bid and best ask, so an exchange with a wide spread doesn’t look cheap on one side and dear on the other. The scoreboard’s premium table compares the middle too.
  • Any exchange within 0.5 basis points of the best price is marked best as well: the top of the book changes hands between exchanges every few seconds, by less than that.

Thin books and low volume

A book whose ask is more than 5% above its bid has no price here. It says Thin, and is left out of the best price, the gap and the rankings: its middle would be a price nobody is dealing near.

A market that traded less than $100K in the last 24 hours is marked Low volume, never hidden: a price there can sit away from where a real order would fill.

How fresh it is

Some exchanges send their prices as they change, and the others are asked for them every few seconds: each exchange’s page says which, and how often. Nothing is guessed or carried over: until an exchange’s figures arrive, its place shows a dot.

On spot, an exchange that has sent nothing for 15 seconds is marked Behind: its prices are still shown, greyed, with their age. After 90 seconds they come off the table until it’s back. The perpetuals index is read every 30 seconds, so its limits are longer: 75 seconds and 3 minutes.

Futures and options are read again every minute on a coin’s page and every 2 minutes elsewhere, and show how old they are.

Stablecoins and your currency

Every figure is worked out in US dollars. Markets priced in USDC, USDT and USDG are converted at the middle of Kraken’s own book for each against the dollar, live; until that rate arrives, they have no dollar price, rather than counting a stablecoin as exactly a dollar. Polymarket Perps’ pUSD, backed one for one by USDC, is converted as USDC.

Choose another currency in Settings (EUR, GBP, CAD, AUD or CHF) and amounts are written in it, at the middle of Kraken’s book for the pair, taken at most every 30 seconds. With no fresh rate for 2 minutes, they go back to dollars and say so. Percentages, basis points and funding rates have no currency.

Fees

Each exchange’s page has its fee schedule as the site uses it, with the day it was read:

The Trade simulator works out what a trade costs at each exchange’s standard taker fee, or at your own tier where you set one, walking the order book for your amount. Signals takes the same fees on both sides of a gap. Fees change: check the exchange’s own schedule before you trade.

Funding, as a rate a year

Exchanges pay funding at different intervals, from every hour to every 8 hours, and Deribit by Coinbase all the time. To compare them, the site shows each as a simple rate a year: the rate for one interval times the number of intervals in a year of 8,760 hours. For example, 0.01% every 8 hours comes to 10.95% a year.

It isn’t compounded, and it’s what holding a position would pay or cost if the rate stayed where it is, which it rarely does. Deribit by Coinbase’s rate is what it paid over the last eight hours.

Signals

Signals lists where two exchanges are apart on a price by more than it costs to trade both sides:

  • A gap counts only if it’s still there after both exchanges’ taker fees; those apart before fees but not after are listed under them.
  • The top 10 gaps on spot are walked down both order books about every minute, to see how much of your amount fits inside the gap.
  • Standing: open the whole 10 minutes its line covers. A price apart that long usually has a reason, such as withdrawals that are slow or shut: look for it first.
  • New: opened since the page began reading. Every signal is timed from when the page opened, and nothing is kept between visits.
  • Thin: one of the two markets traded under $100K in the last 24 hours. Marked and listed after the others, never hidden.
  • Funding spread trade: short a perpetual where its funding is highest and long it where it’s lowest, with a day’s net after both fees to open, and the spread over the last seven days where both exchanges publish their history.

A signal says where prices are apart, not which way they’ll go, and it isn’t advice: a gap can close before an order reaches it.

Futures and options

Options are compared by their implied volatility, not their price: each exchange prices from its own forward, and volatility takes that out. At the money is the strike nearest the forward that at least two exchanges list, so they’re compared on the same contract.

A dated future is compared by its premium a year: its price at the middle of its book over its own exchange’s index, as a simple rate a year. None is shown within 7 days of expiry, where a hair’s difference becomes a large rate, or where half its book’s spread comes to more than 1 point a year.

Max pain is the settlement price at which an expiry’s options, on every exchange together, would pay out least. Open interest in dollars is counted at one price for every exchange, so the shares compare positions, not prices.

Options are read from Deribit by Coinbase, OKX and Bybit, and dated futures from 7 exchanges, whatever you have switched on, unless you choose “Only exchanges I use” on the scoreboard or an exchange’s page.

What it can’t tell you

  • A price is the book at this moment. By the time an order arrives it may have moved, and a large order fills deeper than the best price: the Trade simulator walks the book to show how far.
  • Some exchanges’ data can’t be read in full by a browser on another website: only the best levels of a book, say, or no open interest. Where an exchange’s data stops short, the page’s notes say so; where it can’t be read at all, it isn’t here.
  • Jupiter and CoW Protocol, which route a swap across many exchanges, and Variational quote prices rather than keep an order book, so they’re shown beside the books, marked Quote, and never ranked against them.
  • Two exchanges’ tokens of the same share can be different issuers’, and some pause outside their market’s trading hours: the page notes both.
  • Not every exchange is open to everyone. One that doesn’t answer your browser shows as not live, with nothing filled in for it; whether you can trade on an exchange is between you and it.

Corrections

Spotted something wrong? Report a wrong number, at the foot of every page: it starts a post to @coinsmash_ on X with the page’s address in it. What’s fixed goes into the changelog with the day it went live, with every other change to the site.

Help says what to put in a report.