In the Beurs van Berlage, built in 1903, grain, goods and securities were traded in the first half of the last century. The Koopmansbeurs was in a different location during Johanna Borski's time, namely on the corner of Dam and Rokin. Although women were not welcome on the trading floor in her time, Borski managed to turn this to her advantage.
As the widow of the second richest resident of Amsterdam and gifted with great business talent, Borski continued her husband's business in 1814. Anyone who wanted to do business with the widow Borski had to ask for help at her home. She led the company to the top of the Amsterdam money market. When the newly founded Nederlandsche Bank failed to complete the share issue in 1816, the widow Borski took over the remaining 40 percent. With the condition that no new shares would be issued for three years, so that she could sell her shares at a profit. Later she provided the Nederlandsche Handel Maatschappij with substantial loans backed by securities. In doing so, she laid the foundation for what is now ABN AMRO. With a fortune of around 4 million guilders, Borski must have been one of the richest people in the country.