1. Leonard N. Stern School of Business, New York University, New York, NY, USA
2. Department of Mathematical Sciences, Tsinghua University, Beijing, China
3. Naveen Jindal School of Management, University of Texas at Dallas, Richardson, TX, USA
4. Yau Mathematical Sciences Center & Department of Mathematical Sciences, Tsinghua University, Beijing, China
5. Beijing Institute of Mathematical Sciences and Application, Beijing, China