1. Department of Finance, HEC Montréal, Montréal, Québec H3T 2A7, Canada;
2. Canadian Derivatives Institute, Montréal, Québec H3T 2A7, Canada;
3. Department of Finance, Università della Svizzera Italiana, 6900 Lugano, Switzerland;
4. Department of Economics, Social Studies, Applied Mathematics, and Statistics, University of Turin, 10124 Turin, Italy;
5. Geneva Finance Research Institute, University of Geneva, 1211 Geneva, Switzerland