This paper assumes as a focal point the concept that the "post-Brexit" may represent a change of era for European and global financial service and particularly for capital market sector. The change of era produces new "global systemic interrelation" in which financial globalization, governance and regulation will give place to new, largely unknown complexities. In general, the different interests and immediate priorities of euro and non-euro countries, coupled with a need for prompt and, at times, politically sensitive action, have had the result of a greater fragmentation or a differentiated integration in EU governance in the financial sector. On this assumption, we may say that the post-Brexit scenario is in some way preceded by a series of "fractures" in European governance. The direct effect of the post-Brexit era is that UK regulated financial entities will still need "passporting" across the EU single market: UK is going to vest the role of third party country, which will require an "equivalence regime" similar to the "substituted compliance" used in the same direction by US regulators.At the same time, while an equivalence regime may work in principle to deal cross-border issues at the global level, in the long term, it may be an instrument for a "battle of ideas" in the new political arena of global financial governance.