Stefan has 20 years of chemical industry experience with emphasis on inorganic and electronic chemicals (i.e. sodium chloride, salt, calcium chloride, boron chemicals, sulfur chemicals, zinc chemicals, oilfiled chemicals, mining chemicals, sodium bicarbonate, lime, limestone, calcium carbonate, hydrochloric acid, hypochlorites, bromine, chromates, silicates and silicas, hydrogen peroxide, H2O2, sodium chlorate). He has authored a broad range of reports for the Chemical Economics Handbook (CEH) and the Specialty Chemicals Update Program (SCUP). In his area of expertise, he managed and conducted market assessments and special studies on market entry and project feasibility. Before joining S&P Global Commodity Insights (then SRI Consulting in Zurich, Switzerland) in 2001, he worked for six years with Metalor SA in Neuchâtel, Switzerland. Earlier, he was an R&D chemist with Chemet Corporation in Attleboro, Massachusetts, United States.

Stefan earned his master's degree from the University of Freiburg, Germany, and received his doctoral degree from the University of Basle, Switzerland.