Cross-exchange perp–perp spread: entry, convergence and exit
The same perpetual future costs different amounts on two exchanges. We buy the cheap one, sell the expensive one and wait for prices to converge. On a real pair we look at what the result is made of and why a spread may never converge to zero.
In lesson 2 we saw why prices of the same coin diverge across exchanges. The most direct way to play it is perp + perp: hold two opposite perpetual contracts on different exchanges and wait for the price gap to shrink.
The scheme
- 1
Long where it is cheaper
Open a long perp on the exchange where the price is lower. - 2
Short where it is pricier
At the same time open a short of the same number of coins on the exchange where the price is higher. The position is neutral to market direction. - 3
Wait for the spread to narrow
If prices on the two exchanges move closer, the long and the short together earn the amount the spread narrowed. - 4
Close both legs
At the same time and with the same number of coins — once the spread reaches the target or the exit rule triggers.
The P2P.Army screener calculates the price spread as (short price − long price) ÷ long price. A positive spread means you sell higher than you buy.
What the result is made of
- Spread convergence: the entry spread minus the exit spread, as a percentage of position size.
- Funding along the way: both legs are perps, so every interval one receives and the other pays. The difference can help or hurt (how funding works).
- Fees: four trades — entry and exit on two legs.
- Slippage: on a thin book, entry and exit are worse than the price in the table.
The MOOUSDT pair: Gate.io LONG, MEXC SHORT
- Prices. The long on Gate.io at 0.00577, the short on MEXC at 0.00584: a spread of +1.2131%.
- Funding. The rate on Gate.io is +0.005%: the long pays. On MEXC it is +0.02%: the short receives. +0.015% per 4 hours in total, about 0.09% a day.
- History. Over the day the spread jumped dozens of times between zero and 6.5%, averaging around 3%. The current 1.21% is the lower part of the range, not the start of convergence.
The conclusion is unpleasant but honest: such a spread is not a temporary imbalance about to disappear but a persistent price gap on a thin market. Entering at 1.21% is a bet on spread swings, not arbitrage with guaranteed convergence.
| Exit spread | Spread result | Minus fees 0.2% |
|---|---|---|
| 0.00% | +1.21% | +1.01% |
| +0.50% | +0.71% | +0.51% |
| +1.21% | 0.00% | −0.20% |
| +3.00% | −1.79% | −1.99% |
| +6.00% | −4.79% | −4.99% |
Why perps may not converge
A dated future has an expiry date, and by then its price must converge with the index (lesson 3). A perpetual has no such date. Funding pulls each exchange toward its own index, but exchanges’ indices differ, and on a thin market an imbalance can last for weeks. If deposits or withdrawals of the coin are closed on one exchange, nobody can move it across, and the spread can live indefinitely.
| More likely to converge | May not converge |
|---|---|
| A large liquid coin on major exchanges | An illiquid coin with a thin order book |
| Deposits and withdrawals are open on both exchanges | Deposits or withdrawals are closed on one exchange |
| The spread appeared suddenly — a liquidation cascade, an outage on one exchange | The spread has lasted a long time and oscillates around one level |
| Funding rates pull prices toward each other | Funding on both exchanges is near zero |
| It is the same coin | Different projects share one ticker |
Set the exit rule before entering
Decide two numbers in advance: a target (for example, the spread narrows to zero or to half of the entry level) and a stop (the spread widens to a level at which you close at a loss so as not to risk your margin). Add a time limit: if the spread has not moved within the agreed period and funding is working against you, the position is eating money.
Frequently asked questions
How do you profit from a futures price gap between exchanges?
Open a long perp where it is cheaper and a short of the same number of coins where it is pricier. If prices converge, both legs together earn the amount the spread narrowed, minus fees and adjusted for funding.
Is the spread guaranteed to converge?
No. A perpetual future has no expiry, so the spread between exchanges can oscillate around a stable level or widen — especially on illiquid coins and when deposits or withdrawals are closed.
Does funding affect the result?
Yes: both legs are perps, and every interval one receives funding while the other pays. The rate difference can add income or eat it while you wait for convergence.
What if the spread widens?
Follow the exit rule set before entering: close both legs at the stop level or add margin if you are prepared to wait. Above all, make sure the short does not approach liquidation.
Sources
- 1.P2P.Army: futures screener — spot and futuresP2P.Army10/31/2026official
- 2.What Are Mark Price and Price Index in USDⓈ-Margined Futures?Binance9/25/2026
- 3.Oracle | Hyperliquid DocsHyperliquid
- 4.P2P.Army: funding rate arbitrage scannerP2P.Army10/31/2026
About the author
Crypto expert, arbitrage trader and investor
Crypto expert and hands-on crypto arbitrage trader, investor and software developer with over 20 years of experience. On the P2P.Army blog he covers exchange news, P2P and cross-exchange arbitrage.
- Crypto arbitrage
- P2P arbitrage
- Cross-exchange arbitrage
- Crypto exchanges
- Investing
- Software development
