In 1991, U.S. Treasury Deputy Assistant Secretary Mike Basham learned that Salomon trader Paul Mozer had been submitting false bids in an attempt to purchase more treasury bonds than permitted by one buyer during the period between December 1990 and May 1991. Salomon was fined $190million for this infraction, and required to set aside $100million in a restitution fund for any injured parties. CEO Gutfreund left the company in August 1991 and a U.S. Securities and Exchange Commission (SEC) settlement resulted in a fine of $100,000 and him being barred from serving as a chief executive of a brokerage firm. The scandal was then documented in the 1993 book "Nightmare on Wall Street". The firm was weakened by the scandal, which led to its acquisition by Travelers Group in 1998.