1. School of Business, East China University of Technology and Science, 200237 Shanghai, China
2. Research Institute of Financial Engineering, East China University of Technology and Science, 200237 Shanghai, China
3. ETH Zurich, Department of Management, Technology and Economics, Scheuchzerstrasse 7, CH-8092 Zurich, Switzerland
4. Swiss Finance Institute, c/o University of Geneva, 40 blvd. Du Pont d'Arve, CH 1211 Geneva 4, Switzerland