To understand funding rates, start with the problem they solve. In crypto, the most traded contracts aren’t actual coins — they’re perpetual futures, bets on the price of a coin that never expire. The catch: with no expiry date, there’s nothing forcing the contract’s price to stay close to the real spot price of the coin.
The funding rate is the mechanism that keeps them tethered. It’s a small payment exchanged between the two sides of the market — long traders (betting up) and short traders (betting down) — usually every eight hours.
Which way does the money flow?
When more people are betting the price will rise, the contract trades slightly above spot. To pull it back down, longs pay shorts. When the crowd is bearish, the reverse happens: shorts pay longs. The size of that payment is the funding rate, usually a tiny fraction of a percent each time.
When funding is consistently positive, holding a short position earns those payments repeatedly. That’s the foundation of “funding rate arbitrage” — a strategy we tested rigorously and ultimately invalidated. The payments were real; the problem was that after costs, they weren’t big enough to matter on unseen data.
The “free money” trap
Funding rates look like free income: just collect the payments. But two things bite. First, you usually need an offsetting position to avoid price risk, which has its own cost. Second, the moment a strategy becomes well known, more traders pile in and the payments shrink. What looked free becomes a rounding error.
A funding rate is a small, recurring payment between long and short traders that keeps perpetual futures anchored to the real price. It’s a mechanism, not a money printer.
- 1Perpetual futures never expire, so funding rates keep their price tied to spot.
- 2When the crowd is bullish, longs pay shorts; when bearish, shorts pay longs.
- 3Funding can look like free yield, but costs and crowding usually erode it.
funding rate — the basis of our Funding Rate Arbitrage postmortem.