Perpetual futures and the funding rate that anchors them
A futures contract with no expiry needs another way to track spot, and periodic payments between longs and shorts do that work.
A perpetual future is a derivative contract on the price of an asset that never expires and never delivers anything. Because there is no settlement date to force convergence with the underlying, the contract uses a recurring payment between the two sides, the funding rate, to pull its price back toward the spot market. In most digital-asset markets, perpetuals trade far more notional than the spot market they reference.
The contract and the two prices it depends on
A trader posts margin and takes a long or short position sized as a multiple of that margin. Profit and loss accrue continuously against a reference. Two distinct prices matter and confusing them causes most avoidable losses. The last traded price is what the contract changes hands at on that venue. The mark price is a calculated value, usually built from an index of several spot venues plus a smoothed basis, and it is what determines unrealized profit and whether a position is liquidated. Venues use a mark price precisely so that a thin book on one venue cannot trigger liquidations by itself, which makes the construction of that index a load-bearing piece of infrastructure and a target for manipulation.
How funding works mechanically
At fixed intervals, commonly every eight hours though several venues now use shorter periods, the venue computes a rate and every open position pays or receives it on its notional size. The payment goes between traders, not to the exchange. The rate normally has two components: a premium term measuring how far the perpetual has traded above or below the index over the interval, and a fixed interest term reflecting the difference in funding cost between the quote currency and the underlying. Venues clamp the result within a maximum and adjust the clamp in stressed conditions.
The logic is a feedback loop rather than a rule about direction. If the contract persistently trades above the index, longs pay shorts, which makes holding a long more expensive and makes selling the contract while buying spot profitable. That trade, the cash-and-carry, is what actually restores convergence; funding just creates the incentive for it. Which means funding is best read as the price of leveraged exposure, set by supply and demand for that leverage.
| Observation | Direct mechanical meaning | What it does not establish |
|---|---|---|
| Persistently positive funding | Longs pay shorts; the contract is trading above the index; leveraged long exposure is in demand | That the price will fall, or that positioning is crowded in any predictive sense |
| Persistently negative funding | Shorts pay longs; the contract trades below the index, often when borrow or spot access is constrained | That the price will rise, or that shorts are trapped |
| Funding spiking to the venue cap | The arbitrage that would flatten it is constrained by capital, credit or transfer limits | A market-wide signal, since caps and index construction differ by venue |
| Funding near zero with high volume | The contract is tracking the index closely and carry is being arbitraged efficiently | That leverage in the system is low |
Basis, contango and backwardation
Dated futures, which do expire, express the same relationship as a term structure. The basis is the gap between the futures price and spot, and it must converge to zero at expiry. When futures trade above spot the curve is in contango, and the annualized basis is close to the return available from buying spot and selling the future to hold to expiry, before financing and counterparty considerations. When futures trade below spot the curve is in backwardation. In equity and commodity markets the basis reflects storage, dividends and financing; here there is no storage cost and no dividend, so the basis is mostly the cost of capital plus the price of leverage demand, which is why it can move far more than an equity index basis would.
What the margin is denominated in changes the payoff
Two versions of the same contract behave differently depending on the collateral. A contract margined in a stablecoin has a linear payoff: each unit of price movement produces the same change in profit regardless of level, and the collateral holds its value while the position runs. A contract margined in the native asset itself, sometimes called an inverse contract, does not. The collateral moves with the market, so a long position that is losing is also collateralized by an asset that is falling, which compounds the effect and pulls the liquidation point closer than the headline leverage suggests. The payoff is convex in one direction and concave in the other. This is a mechanical property of the contract specification rather than a matter of preference, and it is the most common source of surprise for someone applying intuition from a linear contract to an inverse one.
Open interest is not volume
Open interest counts contracts currently outstanding, while volume counts contracts traded in a period. A day of enormous volume can end with open interest unchanged if positions were opened and closed within it, and a quiet day can see open interest build steadily. The pairing matters: open interest rising alongside price indicates new positions financing the move, while a sharp fall in open interest during a price move indicates positions being closed or liquidated rather than new conviction. Neither pattern predicts the next move, and both are reported per venue, so aggregate figures depend on which venues a data provider covers.
The plumbing that decides who pays for losses
When a position is closed by the venue and the remaining margin does not cover the loss, the shortfall goes somewhere. Venues maintain an insurance fund built from liquidations closed at better-than-bankruptcy prices, and when that is exhausted many use auto-deleveraging, which force-closes profitable positions on the other side to balance the book. That is a socialization of loss, and it means a correct position can be closed against the holder's wishes through no fault of the position. This machinery exists because there is no clearing house standing behind these contracts and no daily settlement window in a market that runs continuously.
Perpetuals connect to nearly everything else in this track: they are the main venue where leverage is expressed, the reason liquidation cascades propagate across assets, and often the place where price moves first. The risk pages cover derivative-related exposures per asset, 24-hour volume and 30-day volatility give the activity and turbulence context that funding readings need, and the glossary holds the individual contract terms.