The European monetary integration process has helped bring financial markets together in Europe, but it's not the only factor. The common currency, the euro, has been most effective in connecting short-term deposits, bonds, and derivatives markets. However, it hasn't been as successful in areas like collateralized instruments and equities due to differences in institutions and cultures. Simply having a common currency isn't enough to fully integrate financial markets; barriers and obstacles still need to be removed for a seamless flow of financial services.