Perpetuals exchanges compared: open interest and funding

Comparing perpetual futures exchanges by trading volume alone misses the two things that matter most to anyone holding a position: where the positions are, and what holding one costs. The first is open interest. The second is funding, paid between longs and shorts every hour or every few hours for as long as a position stays open. The site's perpetuals scoreboard ranks every exchange on both, live, on the coins they share.

Open interest or volume: which says an exchange is big?

Volume counts every trade in a day. Open interest counts what's still open after them: the value of every position held on the exchange's perpetuals (open interest explained). They measure different things. An exchange where positions turn over fast can trade a lot and hold little; one where traders hold for weeks can trade less and hold more.

The scoreboard shows both, each with its share of every exchange's, and opens sorted by open interest: where traders keep their positions. Hover a volume figure for open interest over the day's volume. High, and positions are held a long time; low, and they change hands fast.

Where is funding cheapest?

Funding is set by each exchange's own traders, so the same coin's rate differs from one exchange to the next (funding rates, side by side). For a long, the cheapest exchange is the one with the lowest rate; for a short, the best paid is the one with the highest. The scoreboard counts, for each exchange, how often it's either, and how far its rates usually sit from everyone else's:

• Lowest funding on, with Long chosen: on how many of its perpetuals its rate is the lowest of every exchange's.
• Highest funding on, with Short chosen: on how many it's the highest.
• Against the rest, the same for either side: on each coin, the exchange's rate less the middle of the other exchanges', then the median across its perpetuals, in points a year. Below zero, its funding usually runs lower than the rest's; above, higher.
• Funding: its median rate a year, across its perpetuals.

How to read the perpetuals scoreboard

1. Open the perpetuals scoreboard. Every exchange with perpetuals is on while it's open, whichever you've chosen, and your own choice comes back the moment you leave.
2. Choose Long or Short, the side you'd hold.
3. Read the four figures over the table: the most open interest, the exchange with the lowest (or highest) funding most often, the one whose funding sits furthest below (or above) the rest, and the funding flow across every exchange.
4. Sort by any column. Sorted by Against the rest, the exchanges whose funding runs highest come first; click the heading again for the lowest.

Example figures, not market data. A holds the most, but B is the cheapest place to hold a long most often, and its funding usually runs below the rest's. C's traders hold their positions longest.

Funding flow: who pays whom

A rate says what holding a position costs; the flow says how much money is moving. Each exchange's Funding flow/hr is its open interest times its funding for an hour, across its perpetuals: what its longs pay its shorts in an hour at today's rates, or its shorts pay its longs where it's below zero. Over the table, the scoreboard adds every exchange's up: which side the whole market is paying, and how fast (funding flow).

Then open an exchange's page

Click an exchange's name and its own perpetuals page opens: Hyperliquid's, for one. Its figures across the top, then coin by coin:

• Funding outliers here: the coins where its funding is furthest from the rest's, with the best other side for the funding spread trade.
• Every perpetual on it: funding now, against the rest, the 7-day average, the next payment, open interest and its share of the coin's.
• Basis: each perpetual's price against the same coin on its own spot market, where it has one.
• Its liquidations, live, every market at once, where its feed publishes them (crypto liquidations explained).
• Its fees, as the Trade simulator on each coin's page uses them.

What the scoreboard leaves out

• Open interest isn't counted the same way everywhere. Each exchange reports its own, and a few publish none a browser can read, so treat the gaps between them as approximate.
• Rates reset. Funding changes at every payment, so who's lowest can change within the hour.
• Fees and depth. Funding is the cost of holding; opening and closing cost a spread and a fee, which the Trade simulator on each coin's page counts.
• Who can use it. Some exchanges don't serve every country, and some of their products aren't open to everyone where they do. Check before you compare what you can't trade.

Not financial advice. Rates move while you read them.