Abstract

The pricing of goods and assets, which in economic terms represents a balance between supply and demand, is also a result of what information is available, that is, the whole of circulating rumours. In a context characterized by uncertainty, pricing will be more significant insofar as it results from the information available to the agents. The financial market is a place where non-material goods are exchanged, goods whose characteristics and qualities the purchaser knows nothing of directly. Therefore market lives on information and rumours and is strongly influenced by these factors. On the other side, market manipulation can heavily alter the information available, which in turn can influence the process of price making itself. These problems are at the origin of specific legislation aimed at the correct functioning of the market, against impediments to competition and uncontrolled exploitation of privileged information. The analysis of the regulation of market abuse in the United States highlights all the characteristics of "common law" countries, where special relevance is attributed to the series of judgements and judicial guidelines which follow one another throughout time. It is case law that indicates what is legal and what is not, although jurisprudential trends can also influence the regulation of the matter. The regulation of insider trading and market manipulation is more recent in Europe. Here the current trend is to try to harmonize the regulation of market abuse in order to guarantee effective control over increasingly integrated financial markets and therefore promote transparency, stability and credibility of the whole system. However, new technologies, the rapidity of the spread of information and the immediate influence these have on the choices of all economic agents pose new problems to the regulating role of those institutions which guarantee growth and economic wellbeing.