He apprenticed in Frankfurt, Amsterdam, Paris, and London. From 1910 until 1938, he was director of M. M. & Company in Hamburg, Germany. As head of that firm, he advised Kaiser Wilhelm II prior to World War I. In the 1930s, despite the rise of the Nazi Party, felt there was hope for the future in Germany and tried to wait out the Nazi crisis.
Beginning in 1933 he served on the board of the German Reichsbank under governor Hjalmar Schacht.
He sold the bank because the 1935 Nuremberg laws set the framework and campaign of “Aryanization”. He then emigrated to the United States in 1938.