Perpetual Futures Funding Rates, Explained Simply

The contract that never expires

A perpetual future — often just called a “perp” — is a derivative contract that lets you bet on or hedge an asset’s price without owning it. Unlike a normal futures contract, it has no expiry date. You can hold it for as long as you keep enough margin in your account. That single design choice is what makes the whole funding-rate story necessary.

A dated futures contract converges toward spot naturally as it approaches settlement. A perp has no such moment. As the CFTC’s Michael S. Selig put it when the agency allowed a US-listed bitcoin perpetual, perps instead have counterparties periodically exchange a funding rate payment to maintain relative price parity with spot. Funding is the stand-in for expiry — a small, recurring nudge that keeps the contract from drifting too far from the reference price.

Who pays whom, and why

Funding is not an exchange fee. It is a transfer between traders. When the perp trades above spot, funding is positive: longs pay shorts. When the perp trades below spot, funding turns negative: shorts pay longs. In each case, the side pushing the price away from spot pays the side willing to lean against it.

The calculation usually has two parts. There is a premium component — how far the perp’s mark price sits from a spot index — and often an interest-rate component that reflects a baseline cost of carry. Some venues clamp the result so it cannot jump abruptly. Binance, for instance, documents a formula of premium plus a clamped interest term, with a default eight-hour interval. That timing matters: at eight-hourly settlement, a position held through a full day crosses three funding events.

The payment applies to the notional value of the position, not just the margin you posted. A useful illustration: a 1 BTC long at roughly 100,000 with a 0.01% funding rate pays about 10 at settlement. Small, yes — but it repeats. Hold that same position at 0.3% per eight-hour interval and you are paying about 0.9% of notional per day, roughly 6.3% over a week. The price doesn’t have to move against you. Funding is a carrying cost, and it compounds.

Why perps often track spot

Academic work on perpetual pricing frames funding as the mechanism that makes divergence costly. Researchers deriving no-arbitrage prices for perps show that the theoretical perp price is proportional to spot, with the ratio shaped by interest rates and the funding formula. A key feature is the clamp: when perp and spot are close, funding sits near a small fixed value; when they diverge, funding rises roughly linearly with the gap, rewarding traders who close it.

But theory and practice differ. Studies of crypto perps find deviations from no-arbitrage benchmarks that are larger than in traditional currency markets, though they tend to shrink over time as arbitrage capital and competition increase. Deviations also tend to move together across different crypto assets, hinting at shared funding and liquidity conditions rather than asset-specific quirks.

There is an important caveat here. Perps do not converge at a fixed date, so the trade that captures a funding spread cannot be unwound at a guaranteed profit on a set timetable. Research describes it instead as random-maturity arbitrage — a positive expected payoff at an uncertain future time, which is not the same as risk-free. As one paper puts it, an arbitrageur must stay liquid longer than the market stays irrational.

How funding feeds back into prices

Funding does more than tether. It also reveals positioning. Persistently positive funding means longs are crowded enough to pay for the privilege of staying long. Persistently negative funding means shorts are crowded. Neither state predicts an immediate reversal. Bitcoin’s aggregate funding was overwhelmingly positive through much of 2024, a year in which the price rose substantially. Crowding can persist for a long time.

The useful signal appears when funding and open interest rise together. Open interest is simply the total value of open contracts. High funding plus high open interest suggests a lot of leveraged capital leaning the same way and paying to stay there. If price then moves sharply against that side, liquidations can cascade — forced closures that push prices further, triggering more closures.

Funding is also tied to mark price, the reference used for margining and liquidation. Some venues define a funding basis that adjusts mark price between settlement times. That means funding can influence how close a leveraged position sits to liquidation, even for someone who isn’t deliberately trading funding at all.

The limits of the mechanism

Funding is a strong tether, not magic. It works only if enough traders can and will take the other side. Capital constraints, borrowing costs, venue credit concerns and fragmented collateral across exchanges can all blunt the response. Caps and clamps, while sensible, mean funding cannot always fully correct an extreme gap. Noisy or fragile price inputs can make the premium measurement unreliable, especially in thinner markets.

Research treating cross-venue funding arbitrage as a basis trade finds that returns are driven mainly by funding carry but are highly assumption-sensitive. Funding and residual market risk account for the largest variance shares; leverage and volatility regime dominate liquidation hazard. Notably, stress tests suggest counterparty-risk episodes can be more damaging than purely directional price crashes. That is a sobering reminder that a spread trade is not just a spread — it carries venue, margin and settlement risk.

Rules differ by where you are

Jurisdiction matters, and so does the substance of what you are trading. In the United States, the CFTC’s May 2026 order permitted one designated contract market to list a bitcoin-referenced perpetual, alongside a policy statement describing how it intends to review further listings. That order covers a specific product; it does not settle which other perps will be approved, or when.

In the United Kingdom, the FCA’s prohibition on selling, marketing or distributing crypto derivatives to retail consumers has been in force since January 2021. In the European Union, ESMA said in February 2026 that derivatives marketed as perpetuals are likely to fall within existing national product intervention measures on contracts for difference, which include leverage limits and negative balance protection. If you are outside these jurisdictions, the rules where you live still apply. This is a description of regulation, not legal advice — and nothing here is a personal recommendation.

What to watch, not what to chase

Funding rates are best read as a positioning price, not a forecast. They tell you who is paying to hold leveraged exposure, and roughly how much. Watched alongside open interest, mark price and liquidation data, they add context about whether a market looks crowded and fragile or balanced and calm. That is genuinely useful. What they do not do is guarantee an outcome.

One light observation, offered gently: in a market where a payment called “funding” flows back and forth every eight hours, the most expensive thing you can hold is often your own conviction. The contract will wait. The funding clock will not.