As a German firm, H. Upmann feared the seizure of U.S. investments during World War I by the Custodian of Alien Enemy properties, and had invested heavily in speculative currency investments and Mexican oil properties, using assets on deposit without the consent of the depositors.
As a German banking firm, H. Upmann's U.S.-based property and asset investments during World War I were seized by the Custodian of Alien Enemy properties, and the firm was placed on the U.S. Enemy Trading List. To compensate, the Hermann Upmann had invested heavily in speculative currency investments and Mexican oil properties, using funds obtained from depositor assets without the consent of the depositors.