The study makes a contribution to the cultural history of the modern art trade in Switzerland, with a focus on the work of Jewish art dealers and gallery owners. These had discovered their spiritual source of inspiration in the art world of Paris - especially in Impressionism and the subsequent art movements as well as with Picasso. The painting The Four Trees (1868/69) by Camille Corot on the cover, which Emil Bührle acquired from Galerie Aktuaryus in 1937, marks this beginning. In their function as art mediators, they established themselves between artists and collectors and thus built up new art worlds. At the intersection of (European) Jewish identity and the history of the reception of art, their personal motives, their professional approaches, their strategic adjustments to the market, their careers and historical circumstances are examined.