The weekend arrest of Russia 's richest man , Mikhail Khodorkovsky , chief executive of oil major YUKOS , on charges of fraud and tax evasion unnerved financial markets .
The weekend arrest of Russia 's richest man , Mikhail Khodorkovsky , chief executive of oil major YUKOS , on charges of fraud and tax evasion unnerved financial markets .
Russian stocks fell after the arrest last Saturday of Mikhail Khodorkovsky , chief executive of Yukos Oil , on charges of fraud and tax evasion .