1. Department of Mathematical Sciences, Tsinghua University, Beijing 100084, People's Republic of China
2. Division of Mathematics, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, People's Republic of China
3. Hangzhou Higgs Asset Management Co., Ltd., Hangzhou, Zhejiang 310000, People's Republic of China
4. Department of Economics, UC Berkeley, Berkeley, CA 94720, USA