From a mechanism design perspective, this "holding + trading" dual-layer incentive is clearly more effective at driving market activity than simply holding rewards. For users who already have positions in the contract market, USD1 just sitting there idle can now be used to maintain a position of 300, allowing them to earn additional bonus returns. Moreover, as a stablecoin, USD1 has low price volatility, making it inherently more convenient as margin for contracts compared to other floating assets, without the need to worry about collateral depreciation.