Maximum Holding Limits are independent for each Master or Sub-account. 

To monitor more real-time changes in the maximum holding limits, refer to our Trading Rules.

API is not supported when purchasing or redeeming BFUSD.

Virtual sub-accounts cannot purchase BFUSD. However, users can purchase BFUSD from their master account and transfer it to their virtual sub-account through this API: POST /sapi/v1/sub-account/futures/internalTransfer