Guillaume read law in the Universities of Fribourg (CH) and Heidelberg (D). After his bar exam, he studied at UPenn, obtaining his LL.M. and a business and law certificate from Wharton (USA). He practiced the bar in Geneva, then joined the leading Swiss consulting firm in financial cross-border matters. Before joining the AMAS, he worked for 6 years at the FINMA, in the Asset management Division.