Tomas Fischer became known for his work on the stock market, which began at Carnegie Fondkommission, where he worked as a broker together with financier Erik Penser.
Later he founded his own firm Fischer & Partners.
In the mid-1980s, Fischer ventured into the publishing industry and bought what was then Författarförlaget, which was renamed Bokförlaget Fischer & Co, now bought by Lind & Co.
He was also interested in art and music and has donated large amounts of art.
During the 1980s, Fischer ended up in the media in connection with the investigation into the murder of Olof Palme, when it emerged that he had financed private detective Ebbe Carlsson's own investigations.
According to the family, the drowning accident took place near Tomas Fischer's home in Sankt Barthélemy in the West Indies.