OI limit

The platform enforces position limits in two ways: the absolute position size, which cannot exceed a specified notional value, and the relative position size, which cannot exceed a defined proportion of the platform's open interest (OI). When the OI limit is triggered, only order cancellations and reduce-only operations are allowed.

For a single user ID, the main and sub-accounts are calculated separately. An open interest (OI) risk control limit is triggered if the total position size exceeds the higher of the following: the notional value threshold of futures positions for that user ID, or the platform's OI × 0.5 × futures position ratio threshold. Since the platform OI is calculated bilaterally (long + short) but the limit is applied unilaterally, a 0.5 multiplier is used.

For a single user, the main and sub-accounts are calculated in aggregate. An open interest (OI) risk control limit is triggered if the total position size exceeds the higher of the following: the notional value threshold for futures positions across the main and sub-accounts, or the platform's OI × 0.5 × futures position ratio threshold. In such cases, both the main and sub-accounts trigger the OI risk control limit.

Note: The total position size is calculated separately for long and short positions and includes both current positions and open orders.

Example:

Under a single user ID, the account holds a long position of 10,000 USDT, a long order of 6,000 USDT, and a short order of 3,000 USDT. The notional value threshold for this user ID is 15,000 USDT, and the futures position ratio threshold is 10%. The platform's OI size is 200,000 USDT. Therefore, the total long position is 10,000 + 6,000 = 16,000 USDT, which is greater than max(15,000, 200,000 × 0.5 × 10%). The long position triggers the OI risk control limit.

Under a single user, the main account holds a long position of 18,000 USDT, and one sub-account holds a long position of 15,000 USDT. The notional value threshold across accounts is 30,000 USDT, and the futures position ratio threshold is 20%. The platform's OI size (long + short) is 200,000 USDT. Therefore, the total long position is 18,000 + 15,000 = 33,000 USDT, which is greater than max(30,000, 200,000 × 0.5 × 20%). The position triggers the OI risk control limit.