To prevent the malicious manipulation of the market, Huobi Futures limits the opening and closing price of USDT-margined swaps for each token.  [The above data and indicators may be adjusted in real time according to market conditions, and adjustments will be made without further notice]   Assume for BTC/USDT swaps, the non-basis price limit range is ±4%, normal hard price limit range is ±6%, and the basis price limit range is ±4%; Within 10 minutes of BTC-USDT swaps generation (No basis price limit)： Highest bid price = min [ spot index ( 1 + 6% ) , spot index ( 1 + 4% ) ] Lowest ask price = max [ spot index ( 1 - 6% ) , spot index ( 1 - 4% ) ] 10 minutes after the BTC/USDT swaps contract is generated: (Basis price limit): Highest bid price = min [ ( Basis average of the past 10 minutes + spot index ) ( 1 + 4% ) , spot index ( 1 + 6% ) ] Lowest ask price = max [ ( Basis average of the past 10 minutes + spot index ) ( 1 - 4% ) , spot index ( 1 - 6% ) ] Rules above apply to both opening and closing positions. If users open long or close short, hard price limit will be triggered when the order price is higher than the highest bid price in the market; if users open short or close long, hard price limit will be triggered when the order price is lower than the lowest ask price.