When Porsche revealed it had amassed control of roughly three-quarters of the shares in Volkswagen Group, shares in the Wolfsburg-based carmaker soared to 1,005 euros, briefly making it the world's biggest company by market value.
Hedge funds which had bet on a decline in the VW stock price made massive losses, prompting them to sue in various courts.
In December 2012, a New York judge dismissed a case brought by hedge funds including Glenhill Capital LP, David Einhorn's Greenlight Capital LP and Chase Coleman's Tiger Global LP, arguing the state was the wrong place to bring such a lawsuit, saying instead that the case was more appropriate for Germany.
Hedge funds have since pressed their case against Porsche's management and supervisory board in courts in Stuttgart, Braunschweig, Hanover and now inFrankfurt.
Porsche SE's attempts to buy VW backfired and pushed it to near-bankruptcy. Instead of buying VW, the company ended up selling its sports car business, Porsche AG, to VW.
German weekly magazine Der Spiegel was first to report that hedge funds are seeking damages from Ferdinand Piech and Wolfgang Porsche.