ABSTRACT
If an inquiry into legal sources of financial markets can be imagined as trying to provide a cross-section of a multi-storey building, each floor of which represents different legal institutes and different legal sources, a logical starting point is the ground floor of the building. One of the legal institutes at the basis of transactions taking place in financial markets is the monetary obligation, an institute which broadly defined also comprises rules on payments and financial instruments. An examination of the changes in the regulation of this institute is paradigmatic of the development of new sources disciplining financial market transactions. Before assessing the consequences of this evolution and the role of new and old forms of regulation, it is necessary to briefly recall the main legal problems and developments surrounding the notion of monetary obligations.
