Volkswagen AG, Europe's largest automaker, just became this year's best performing stock on the continent, benefiting from hedge-fund trading strategies and the collapse of Lehman Brothers Holdings Inc.

Volkswagen shares are up 87 percent this year, and the company was one of only four in the Dow Jones Stoxx 600 Index that advanced on Monday in the worst decline for the European gauge since October 1987.

The German company surpassed Toyota Motor Corp as the world's biggest carmaker by market value.