The Colorado Springs-Stetson Hills Public Building Authority (Authority) issued bonds to finance a real estate development in 1988. Central Bank of Denver (defendant) was the trustee for the bonds. This position required Central Bank to determine whether Authority was in a sound financial state. In 1988, Authority defaulted on the bonds. First Interstate Bank of Denver (plaintiff) then brought suit against Central Bank, alleging that it had aided and abetted Authority with securities fraud in violation of § 10(b) of the Exchange Act. The lower court ruled in favor of First Interstate. Central Bank then petitioned for certiorari to the United States Supreme Court.