A reverse cash-and-carry trade sells a coin on the spot market, usually with borrowed coins, and goes long the same amount in perpetual futures to collect funding while funding is negative. It is the mirror of cash and carry. The table on this page shows the best spot and perp pair per coin with negative funding. For the theory, read the reverse cash-and-carry guide.
How it works
- Find a coin with negative funding. When the perpetual trades below spot, shorts pay longs. See what is a funding rate.
- Borrow the coin through a margin account, unless you already hold it. Check the borrow rate and the amount available before you trade.
- Sell the borrowed coin on the spot market at the bid. This is a spot short; see short selling crypto.
- Go long the perpetual in equal size at the ask. You are now delta-neutral.
- Collect funding each interval while it stays negative, and pay borrow interest on the spot loan.
- Exit by closing the perp, buying the coin back on spot and repaying the loan.
Reading the scanner
The scanner covers exchanges where ArbTide collects spot prices, perpetual prices and funding rates together, so venues that publish only one of these are left out.
The columns match the cash and carry scanner, with the direction reversed. Choose a holding period (7, 30 or 90 days) above the table.
Shorting spot means borrowing the coin, so the scanner only uses spot legs on exchanges that offer margin borrowing, and it skips coins an exchange does not lend, including coins missing from the lending lists Binance, OKX and Bybit publish. Under the funding APR, each row shows the borrow rate for that coin. It is subtracted from the estimated APR and the break-even period. Binance, OKX and Bybit publish their rates. On other margin exchanges the row shows an estimate, marked "est.", taken from the median of the published rates for that coin; when no exchange publishes one, it reads "borrow cost unknown". Check the real rate on the exchange before you trade.
- Route: the spot market you sell and the perp you buy.
- Est. APR (holding period): the annualized return after basis and taker fees, if funding stays at its current rate. The line below is the net return over the period. Borrow interest is subtracted where a rate is known or estimated.
- Funding APR: the perp's current funding annualized (rate ÷ interval hours × 8,760), with the raw rate per interval. Here it is negative, which is what the long leg receives.
- Basis: the gap between the spot price you sell at and the perp price you buy at. A positive figure means you sell spot above the perp price, which adds to the return when the gap closes.
- Fees: taker fees on both legs, entry and exit. The line below is the break-even period after borrow costs.
- 24h volume: trading volume for the coin; markets under $100,000 are excluded.
To judge a row, subtract the borrow rate yourself. For example, assume Est. APR shows 25% and the exchange charges 18% a year to borrow the coin: the real estimate is closer to 7%, and the break-even period is much longer than the table shows. Also check how long funding has been negative on the coin's funding history. Deep negative funding often follows a sharp sell-off and can snap back to positive within hours.
Costs and risks the scanner does not include
- Spot borrow interest: often the largest cost. Rates differ by exchange and coin, change over time, and can spike when many traders short the same coin.
- Borrowable supply: the lending pool can run out, so you may not be able to open or add to the spot short. Some exchanges can also recall loans or restrict borrowing.
- Margin liquidation on the spot short: if the price rises, the borrowed position needs more collateral and can be liquidated.
- Funding changes: negative funding can flip positive, and then the long leg pays.
- Cross-exchange routes: the spot short and the perp long may sit on different venues, so a gain on one cannot cover a margin call on the other.
- Slippage and exchange risk on both legs. See arbitrage risks.
Formulas are on the methodology page.
When it works best
Reverse cash and carry pays when funding stays negative for days, usually during extended bearish periods or heavy hedging, and when borrowing the coin is cheap and plentiful. It is most practical on large, liquid coins that exchanges lend in size, and on same-exchange routes where the margin short and the perp long share one account. Short spikes of negative funding rarely cover the borrow cost and four taker fills.