Diversity of systems. In the context of market infrastructures, the notion of system refers to four varieties: trading systems, clearing systems, securities settlement systems and payment systems.These systems have distinct regimes depending on their purpose, which requires a closer look at their respective functioning (Section 1), before showing that they have in common that they are contracts (Section 2).

Section 1. MARKET INFRASTRUCTURE SYSTEMS

The different systems will be presented according to their sources. Indeed, while the law on trading systems originates from MiFID 2 (§ 1), the law on payment, clearing and settlement systems originates from the Finality Directive (§ 2). However, there is no common regime for the supervision of systems (§ 3).

§ 1. TRADING SYSTEMS

Notion of trading systems. Among the different varieties, trading systems are the most important in that they constitute the financial market in the strict sense of the term: they organise trading and determine the price of transactions. It should be noted that there are different ways of matching orders and, consequently, different categories of trading platforms: regulated markets, multilateral trading facilities and organised trading systems.Despite this diversity, the unity of the notion of trading platform stems from the fact that they always constitute a multilateral system. MiFID 2 defines the latter concept as ‘a system or arrangement within which multiple third-party buying and selling interests in financial instruments may interact’.In addition to this first criterion, which is based on the system's function, there is a second criterion that is specific to the manager's role in these negotiations.Indeed, for a market to be qualified as a ‘multilateral system’, case law states that the manager must not intervene in a personal capacity in the negotiations.This common function of organising the negotiations and the manager's independence, however, leaves a great deal of room for the different ways of organising the negotiations, which is reflected in the scope of these rules.