1. School of Mathematics and Statistics, Nanjing University of Information Science & Technology, No. 219 Nanjing, Jiangsu, China
2. Haskayne School of Business, University of Calgary, 2500 University Dr NW, Calgary, Canada
3. School of Mathematics, University of Adelaide, Adelaide SA 5000, Australia
4. Centre for Applied Financial Studies, University of South Australia, Adelaide SA 5001, Australia