German regulators are analyzing a torrent of panicky trading in Volkswagen shares that at one point Tuesday turned VW into the world 's most valuable company while wreaking havoc with several big banks and hedge funds Shares in the German automaker rose as high as 1,005 euros , or $ 1,258 Tuesday after surging 146 percent to 471 euros Monday , the day after Porsche , a rival seeking to build up one of Europe 's great automotive dynasties , said it had effectively gained 75 percent of VW 's voting shares .