بحث موثق بالمصادر: Binance / OKX / Bybit

Why perpetual contracts need funding

A traditional futures contract expires, and on expiry its price must meet the spot price. A perpetual contract never expires, so something else has to keep its price close to the underlying asset. Binance's own explanation is that perpetuals behave much like spot trading pairs, and the funding rate is the mechanism that pulls the contract price toward the index.

The logic is simple. If the perpetual trades above spot because more traders want to be long, the funding rate turns positive and longs pay shorts. That makes holding a long more expensive and holding a short more rewarding, which pushes the two prices back together. When the contract trades below spot, the rate turns negative and the flow reverses.

The formula, step by step

All three exchanges publish the same core structure.

1. Interest rate. Binance fixes it at 0.03% a day by default, which is 0.01% per 8-hour interval. Bybit states the same 0.03% a day, divided by the number of intervals. OKX states 0.01%, fixed across all settlement intervals. Some pairs, such as ETHBTC on Binance or USDCUSDT on Bybit, use 0%.

2. Premium index. This measures the gap between the contract and the spot index, using the price at which a standard-sized order could actually fill on each side of the order book (the "impact bid" and "impact ask"):

Premium index = [max(0, impact bid − index) − max(0, index − impact ask)] / index

The "standard size" is set by margin: on Binance it is the notional you could trade with 200 USDT of margin at maximum leverage, and on OKX it is 200 × the maximum leverage. Binance samples the premium every 5 seconds, which is 5,760 data points over 8 hours. OKX and Bybit compute it every minute.

3. Averaging. The premium is averaged over the interval with later readings weighted more heavily, so the rate drifts toward its final value as settlement approaches.

4. The clamp. Funding rate = average premium + clamp(interest − average premium, −0.05%, +0.05%). In plain terms, Binance notes that as long as the premium stays between −0.04% and 0.06%, the funding rate equals the 0.01% interest rate. That is why the most common funding rate you see on calm days is exactly 0.0100%.

5. Caps and floors. Each contract has a maximum and minimum rate. On Binance at the time of writing, BTCUSDT was capped at ±0.30% per interval and smaller contracts such as ERAUSDT at ±2.00%. Bybit's default limit is the smaller of (initial margin rate − maintenance margin rate) × 0.75 and the maintenance margin rate, and it says a contract that hits the limit automatically switches to hourly settlement.

When funding is charged

The default schedule on Binance and OKX is every 8 hours, at 00:00, 08:00 and 16:00 UTC. Many contracts run on shorter cycles: OKX lists 1, 2, 4 and 8 hours as possible intervals and divides the rate by 8/N so the daily-equivalent cost stays comparable. On Binance, ERAUSDT, MAGICUSDT and STRKUSDT settle every 4 hours.

Three timing details matter:

• You pay or receive only if you hold a position at the settlement moment. Close before it and you are exempt.
• Settlement is not instantaneous. Binance warns of a 15-second deviation and OKX says assessment may take up to a minute; a position opened at 08:00:05 UTC can still be charged.
• OKX says that if a perpetual is delisted before an assessment, that cycle's funding is void.

How much it costs: worked examples

The calculation is position notional × funding rate. Notional is the mark price times your contract size, not your margin, so leverage multiplies funding cost against your capital.

A calm market. A 10,000 USDT BTC long at the standard 0.01% pays 1 USDT per 8-hour interval, 3 USDT a day. Opening and closing that position with market orders at a 0.05% taker fee costs 10 USDT in total. Hold it for 10 days at the same rate and funding (30 USDT) is three times your trading fees. A constant 0.01% every 8 hours adds up to about 10.95% a year of notional.

A stressed market. Binance's ERAUSDT perpetual, on a 4-hour cycle, settled at −1.006% at 12:00 UTC on 10 October, then −0.748%, −0.382%, −0.598% and −0.413% through 04:00 UTC on 11 October. Over those five settlements, shorts paid longs about 3.15% of notional. A 1,000 USDT short held through all five paid roughly 31 USDT, before any price move. At 05:57 UTC the next ERAUSDT rate was estimated at −1.15%.

Today's majors. At the same time, BTCUSDT on Binance stood at −0.00085% and ETHUSDT at −0.011%, both slightly negative, meaning shorts were paying longs small amounts. NexuAlpha's market snapshot at 05:53 UTC showed OKX's BTC rate close to zero as well.

How traders use the funding rate

• As a cost to plan for. Before holding a leveraged position for days, multiply notional by the rate and the number of settlements. If the rate is against you, funding can turn a flat trade into a loss.
• As a crowding signal. A persistently high positive rate means longs are paying to stay in, and a deeply negative one means shorts are crowded. Neither predicts direction, but crowded positions are the ones that get liquidated in sharp moves. Our liquidation tracker shows where that has happened recently.
• As a reason to compare venues. The same contract can carry different rates on different exchanges at the same moment because order books differ. Our funding-rate board shows Binance and OKX side by side.

Binance users can also turn on a funding fee alert in the futures settings; the default threshold is 0.25%.

How to act on this

Funding is a transfer between traders, so no fee rebate reduces it. What you can reduce is the trading fee you pay to open and close the position, which is the other half of the cost. Compare that with the other partner exchanges on /rates and the OKX profile. For how leverage and liquidity interact in a crash, see our analysis of the 10 October 2025 crash one year on.

Quick answers

Who pays funding when the rate is positive? Longs pay shorts. When it is negative, shorts pay longs.

Does the exchange take a cut? Binance and OKX both state they charge no fee on funding; it passes directly between traders.

How often is funding paid? Every 8 hours by default (00:00, 08:00, 16:00 UTC), but many contracts use 1, 2 or 4-hour cycles.

Do I pay funding if I close before settlement? No. Only positions open at the settlement time pay or receive.

Why is the rate so often exactly 0.01%? Because the clamp sets the rate to the 0.01% interest rate whenever the premium is between −0.04% and 0.06%.

Limits

Formulas and schedules come from Binance's, OKX's and Bybit's official help pages; the live rates and the ERAUSDT history come from Binance's public futures data at about 05:57 UTC on 11 October 2026 and will have changed. The worked examples are our arithmetic and assume constant notional. Exchanges can change intervals, caps and the interest rate without notice. This is an explainer, not investment advice. Partner links may earn NexuAlpha a commission paid by the exchange, at no extra cost to you.