Introduction The concept of ‘market abuse’ is widely used in the financial sphere because market abuse can significantly influence the reputation of the financial market among investors. In order to guarantee the economic and financial growth, investors are interested in receiving the complete information regarding the business’s progress and capital related to the market. Still, the national market can see the threat of being avoided by investors if there are improper regulations regarding the market abuse. From this point, it is important to define market abuse as the specific behaviour that contributes to creating false impressions and affects investments negatively because of the issues of insider dealing and market manipulation. Thus, insider dealing and market manipulation are usually discussed as the main types of market abuse, but there is a range of other behaviours that should be discussed as this type of the market failure 3 . As a result, ad hoc publicity is also discussed in the context of market abuse 4 . In this context, market abuse is associated with the behaviour of persons interested in receiving personal advantages from investment and other financial operations. In order to conclude regarding the integrity of the market and effectiveness of proposed regulations to address the market abuse, it is important to understand what aspects of market abuse are identified as influential for the financial market by the European Commission and by the UK authorities. This paper will present the critical analysis of the concept of ‘market abuse’ and its specific scope in the context of the EU and UK legislation, and it will provide the discussion of the market abuse types important to be determined and addressed with references to different regulations. Concept of ‘Market Abuse’ in the Context of UK Legislation The discussion of the concept of ‘market abuse’ in the context of the market failure can be referred to Adam Smith’s views on the principles of the free market and on protection of the right for free decision. According to Smith, it is important to provide strategies and measures that are effective to protect the financial market from the failure, and the main focus is on providing the fair market laws . Such economists and researchers as Gray and Moloney developed Smith’s idea of market failure and concentrated on the necessity of guaranteeing integrity of financial markets. In the context of the United Kingdom, the situation in the market before 2000 demonstrated that there are many signs of the market failure, and existing regulations were not effective to address the problem in terms of controlling insider dealing and market manipulation in order to promote integrity. Although the necessity of new restrictions that could affect the development of financial markets was questionable in relation to the opinions of some economists, the new regulations were proposed for the UK context. Before the year of 2000, equity markets and businesses in the United Kingdom significantly suffered from a range of market failures, including inadequate pricing, issues of insider dealing and market manipulation, and problems with accounting and auditing. The problem was in the fact that many agents in the market chose the strategy of unfair behaviour, and having the opportunity to control the flow of information, they misled investors and persons interested in the valu