Oil prices sink in sudden move after unexpected surge in crude stockpiles
U.S. commercial crude inventories rose by 5.8 million barrels in the last week, compared with analysts' expectations for an decrease of 1.6 million barrels. OPEC may decide to raise oil output as soon as June due to worries over Iranian and Venezuelan supply. Oil prices have gained nearly 20 percent so far this year, with Brent briefly rising above $80.