(27)Overall Union trading in a multitude of shares admitted on the Swiss exchanges is of such frequency that investment firms in the Union could not avail themselves of the exception set out in Article 23(1)(a) of Regulation (EU) No 600/2014. This implies that the trading obligation set out in Article 23(1) of Regulation (EU) No 600/2014 would apply to a significant number of shares admitted to trading in Switzerland.