Allianz Global Investors U.S. (AGI) and three former portfolio managers were charged Tuesday with lying to investors about a complex options trading strategy, as well as forging documents to cover up the scheme, leading to multibillion dollar losses.

AGI admitted the misconduct and agreed to pay more than $1 billion to settle fraud charges announced by the Securities and Exchange Commission (SEC). Together with its parent company, Germany-based Allianz SE, the entities will pay more than $5 billion in restitution to victims.