An upturn in internet trading volumes has boosted pre-tax profits for Comdirect, the online brokerage owned by German bank Commerzbank, after private investors flooded back into the market in the second quarter.

Comdirect posted second quarter pre-tax profits of €10.4m ($11.8m), more than double the €4.7m it made in the first quarter. According to Achim Kassow, Comdirect's chief executive, it is the best quarterly result since the company went public.