Volkswagen takes pole position. Volkswagen (VLKAY.PK) surpassed ExxonMobil (XOM) to become the world's biggest company by market cap after Porsche announced plans to raise its stake in the German carmaker to 75% from 42.6%, triggering a short squeeze. Shares rose as much as 93% yesterday, and were up another 55% in Frankfurt this morning, bringing its market value to â¬296B ($370) vs. Exxon's $343B. As of Oct. 23, almost 13% of Volkswagen's shares were on loan, mostly to short sellers who were forced to swallow massive losses and exit their positions. "Volkswagen has been one of the greatest shorts of hedge funds, and it's been an absolute, absolute disaster," GLG Partner's Emmanuel Roman said. Elsewhere around the globe, carmakers are struggling with plunging sales and a lack of cash. ------------------------- This is a timely warning to shorts everywhere.