USDT-margined perpetual futures contracts do not have an expiration or delivery date. To keep their prices aligned with the spot market, a funding rate mechanism is used.

Each USDT-margined perpetual futures trading pair has a specific funding interval, which may be every 8 hours, 4 hours, or 1 hour. You can view the details for each pair on the Contract Details page.

Example: For the BTCUSDT pair, the funding interval is every 8 hours, specifically: 00:00-08:00 - settlement at 08:00; 08:00-16:00 - settlement at 16:00; 16:00-00:00 (next day) - settlement at 00:00. (All times in UTC+8.)

Only users holding open positions at the time of settlement will pay or receive funding fees. If your positions are closed before that time, no funding fee will be charged or received.

Paying or receiving a funding fee depends on the funding rate and your position direction. When the funding rate is positive, longs pay short; when the funding rate is negative, shorts pay longs.

Funding fees are settled between the users, and the platform does not take any fees from them.

 

I. How Funding Fees Are Calculated

Funding fees are calculated using the following formula:

Funding fee = Net positions * Face value per contract * Settlement price * Funding rate

* Net positions = Number of long futures contracts - Number of short futures contracts.

Funding fees are settled at the index price.

When the funding rate is positive (> 0): If your net positions are positive (> 0), you pay a funding fee. If your net positions are negative (< 0), you receive a funding fee. When the funding rate is negative (< 0): If your net positions are positive (> 0), you receive a funding fee. If your net positions are negative (< 0), you pay a funding fee.

Note: For futures contracts that support both cross margin and isolated margin modes, funding fees are calculated separately for each margin type.

 

II. How the Funding Rate Is Calculated

Funding rates are calculated based on the average premium index within each settlement period. For example, if the funding settlement occurs at 16:00 (UTC+8), the rate is derived from the average premium index between 08:00 and 16:00 (UTC+8). Please note that the funding rate may fluctuate until the funding payment deadline, so it is important to manage your positions based on the actual conditions.

 

1) Premium Index Calculation

The USDT-margined perpetual contract may trade at a premium or discount relative to its fair price. The premium index measures the degree of deviation between the perpetual contract and the spot index price and is used to adjust the funding rate. Higher premiums refer to higher funding rates, incentivizing shorting, while lower premiums indicate lower funding rates, incentivizing longing. This mechanism helps bring contract prices back in line with the underlying spot price.

 

a. Impact Bid/Ask Price

Impact bid price is the average fill price to execute the bid side's impact margin notional, from bid 1 to accumulated bids of N USDT.

Impact ask price is the average fill price to execute the ask side's impact margin notional, from ask 1 to accumulated offers of N USDT.

The range of values for N is as follows:

USDT-M Perpetual	Impact Margin Notional for Impact Bid Price	Impact Margin Notional for Impact Ask Price
BTC and ETH	25,000 USDT	25,000 USDT
LTC, ETC, TRX, XRP, ADA, LINK, DOGE, BNB, UNI, SOL, and SHIB	15,000 USDT	15,000 USDT
BCH, BSV, ATOM, XLM, XMR, ALGO, DOT, THETA, FIL, COMP, KAVA, LRC, WAVES, SNX, KSM, STEEM, FTT, MANA, SUSHI, YFI, AVAX, NEAR, AAVE, CHZ, FRONT, FTM, GAS, GRT, LUNA, CRV, MATIC, SAND, TRB, ACH, ONE, MASK, AXS, DYDX, APE, GMT, GAL, OP, LUNC, APT, TON, BONK, BLUR, CFX, SSV, FLOKI, AGIX, FET, ARB, PEPE, AIDOGE, SUI, ORDI, WLD, SEI, CYBER, BIGTIME, SATS, RATS, WIF, and ENA	8,000 USDT	8,000 USDT
MKR, STORJ, BTT, 1INCH, CKB, EGLD, INJ, JST, SNT, ICP, LPT, MINA, YGG, GALA, ENS, IMX, PEOPLE, METIS, RDNT, STG, LADYS, CAKE, TIA, PYTH, TOKEN, STX, JTO, ACE, BAKE, AI, MANTA, ONDO, ALT, JUP, ID, MAVIA, PIXEL, STRK, PORTAL, KAS, PENDLE, MYRO, AEVO, BOME, ETHFI, ZK, W, TNSR, SAGA, TAO, OMNI, and MERL	4,000 USDT	4,000 USDT
IOTA, OGN, ARK, MEME, LINA, WIN, CORE, LDO, USTC, and new listings	2,000 USDT	2,000 USDT

(The table does not include all listings on HTX; data for reference only.)

 

b. Premium Index

The premium index reflects the current premium, resulting from the combination of the funding basis rate and the deviation of the impact bid/ask price from the index price.

Premium index = [Max (0, Impact bid price - Index price) - Max (0, Index price - Impact ask price)] / Index price

The premium index is calculated every 5 seconds. Each minute generates 12 premium index readings. For an 8-hour funding interval, there are 5,760 data points in total.

 

c. Average Premium Index (P)

Average premium index = (Premium index 1 * 1 + Premium index 2 * 2 + Premium index 3 * 3... + Premium index n * n) / (1 + 2 + 3 +...+ n).

Premium index 1 refers to the first premium index value, and so on.

n = 60 / 5 * 60 * 8 = 5,760 (for an 8-hour interval).

 

2) Funding Rate Formula

Funding rate = clamp {[Average premium index + clamp (0.01% - Average premium index, Premium deviation cap, Premium deviation floor)] / (8/N), Funding rate cap, Funding rate floor}

In this formula, clamp is a function that restricts a value to a specified range. If the value exceeds the upper or lower limit, it is set to the corresponding boundary. The clamp(a, max, min) function works like this: If a > max, the result is max. If a < min, the result is min. If max ≥ a ≥ min, the result is a.

N refers to a funding interval (from 1 to 8 hours, integer). The funding interval is dynamically adjusted and will take effect immediately after the adjustment. Example: If a contract's funding interval changes to 4 hours, then N = 4.

 

The final predicted funding rate is then limited by the Funding Rate Cap and Floor, guaranteeing that the final value also remains within the range.

• Take BTC as an example

Contract	Premium Deviation Cap	Premium Deviation Floor	Funding Rate Cap	Funding Rate Floor
BTC	0.05%	-0.05%	0.375%	-0.375%

View the limits on more contracts>>

(The above data and indicators may be adjusted in real time based on market conditions without prior notice.)

 

III. Additional Funding Fee Rule

Funding fees are collected at the time of settlement. For users with low margin ratios, the system may partially or fully waive their funding fee to prevent forced liquidation.

Maximum payable funding fee = max (0, Static equity - Adjustment factor * abs (Net positions) * Face value per contract * Settlement price / Leverage)

 

IV. Risk Reminder

Under extreme market conditions, HTX reserves the right to adjust the upper and lower limits of funding rates, and modify the funding interval from the default 8 hours. Please note that funding fees (if any) are deducted from your Futures wallet available balance. If your wallet balance is insufficient, the fees will be deducted from your position margin, which may affect your liquidation price. Please manage your positions accordingly to avoid liquidation risks.

 

V. Disclaimer

While our systems aim for accuracy, high processing loads can cause a delay of a few seconds in the funding fee settlements. This means that if a trade is executed very close to a settlement moment, it might be included in a slightly earlier or later batch, which can affect the exact fee amount. The platform does not provide compensation for such occurrences. We advise factoring this into your risk management.