(9)For reasons of legal certainty and because of the need for a level playing field within the Union, a single set of regulations for all market participants is a key element for the functioning of the internal market. In order to avoid market distortions and regulatory arbitrage, prudential minimum requirements should therefore ensure maximum harmonisation. As a consequence, the transitional periods provided for in this Regulation are essential for the smooth implementation of this Regulation and to avoid uncertainty for the markets.