Porsche is being investigated by German financial regulators over allegations that it manipulated the market when it made billions of dollars from hedge funds whilst buying up shares in Volkswagen.  Porsche took the hedge funds by surprise by quietly buying up stock in VW at a time when hedge funds thought the stock was over-valued so were short selling the stock (borrowing shares from other parties, selling them with a view to buying back enough shares to refund their borrowing at a lower cost when the share price has dropped hence making money). Porsche had bought up such a massive proportion of VW that there was the unprecedented situation where there was not enough shares available on the open market for the short sellers to close their positions. Porsche then released shares to the market, the demand for which drove the price up from around €200 to a high of €1005. On paper this made Volkswagen the most valuable company in the world for a short while. It is estimated that Porsche made between €6Bn and €12Bn in the frenzied trading back in October.