Adjust Tier 5 Referral Code Referees' Discount Rate

To help top-tier referrers attract more trading volume, :gem: :raised_hands: tier referral codes’ referee trading fee discount rate will increase from 5% to 10%.

This update will become effective on Jan. 31st, UTC, 2023. The MUX team will continue to evaluate and provide a better user experience. We will make more improvements in the future based on analyses. Please let us know if you have any questions.