MASS: Multi-Agent Simulation Scaling for Portfolio Construction. - Taian Guo; Haiyang Shen; Jinsheng Huang; Zhengyang Mao; Junyu Luo 002; Zhuoru Chen; Xuhui Liu; Bingyu Xia; Luchen Liu; Yun Ma 002; Ming Zhang 004 (CoRR, 2025)