What defines an investment market under regulation?

An investment market is defined under regulation by its ability to meet specific criteria, particularly the Markets in Financial Instruments Directive (MiFID) requirements, and to have recognition by the Financial Conduct Authority (FCA) in the UK. MiFID establishes a standardized framework for investment services across the European Union, focusing on transparency, investor protection, and the integrity of markets. By adhering to these requirements, a market ensures that it operates under a well-regulated system which fosters trust among investors and maintains orderly market practices.

Recognition by the FCA further solidifies the legitimacy of the market, as the FCA serves as the regulatory body that oversees financial markets in the UK, ensuring compliance with various standards designed to protect investors and promote market integrity. This combination of MiFID compliance and FCA recognition is crucial for an investment market's operational legitimacy and is a fundamental component of regulatory frameworks governing investment markets.

The other options, while they may contain some elements related to market functionality, do not encompass the essential regulatory framework necessary to define an investment market effectively.