1. School of Finance, Zhongnan University of Economics and Law, Wuhan 430073, China
2. School of Statistics and Mathematics, Zhongnan University of Economics and Law, Wuhan 430073, China
3. School of Mathematical Sciences, Monash University, Melbourne, VIC 3800, Australia
4. Brandeis International Business School, Brandeis University, Waltham,MA 02453, USA
5. Department of Finance, Wuhan Technology and Business University, Wuhan 430065, China