Outside the majestic Wittenbergplatz subway station in Berlin, activist Hedda tells people passing by that the majority of the superrich in Germany inherited their wealth.

Striding back and forth in front of a massive banner accompanied by other protesters and a big polar bear in a pink cape, she cites an analysis that found only one in four billionaires is self-made in the country.

"Which tax can the government use to fairly redistribute this excessive wealth generated by genetic lottery?" Hedda shouted.

"Inheritance tax!" someone yelled back. The activists, who are part of a group that calls itself NoSuperReturn, cheer and someone hands the person a golden chocolate coin.

It's a lively kickoff to a week of protests around SuperReturn, a private equity conference in the German capital that brings together participants representing more than $50 trillion (€43 trillion) in assets under management, according to its organizers.