The proportion of European equity trading taking place on dark pools tracked by US broker Rosenblatt Securities has fallen for the first time, as the off-exchange venues failed to match growth in the overall market in 2015.

Around 5.7% of all European stock trading in 2015 took place on the dark pools that Rosenblatt tracks, compared with 6.5% in 2014. It was the first time that figure had fallen since the broker started collecting the data in 2008.