The Act of August 2, 2002 on the supervision of the financial sector and the financial services fundamentally reforms the organisation and supervision of the Belgian secondary markets for financial instruments. The Act is inspired by the recommendations on the reform of the European securities markets formulated by the Committee of Wise Men presided by Mr. Lamfalussy; it anticipates on the implementation of the EU Market Abuse Directive and modernises the conduct of business rules for financial intermediaries. The present paper focuses on the innovations in the Act, which will have animpact on the activities of Belgian credit institutions within a purely Belgian context and a wider European context. Critical remarks are made on the new supervisory regime for secondary markets and alternative trading systems, the framework for in-house order matching, the new conduct of business rules for financial intermediaries and the administrative regime for market abuse. The author concludes by welcoming the new rulemaking process regarding conduct of business providing for an open consultation procedure involving the financial sector.