Oil prices slid about 2 percent on Thursday, extending the previous session's dive that brought prices to the lowest levels this year, as record U.S. crude inventories fed doubts about whether OPEC-led supply cuts would reduce a global glut.
U.S. crude prices fell through the $50 a barrel support level, with market participants unwinding some of the massive number of bullish wagers they had amassed after a deal by top global oil producers to limit output.
The losses followed Wednesday's slide of more than 5 percent, the steepest in a year, after data showed crude stocks in the United States, the world's top oil consumer, swelled by 8.2 million barrels last week to a record 528.4 million barrels, far surpassing forecasts for a 2 million barrel build.
"It was one month ago yesterday that the market got hit on a big increase in supply only to (have prices) rebound and start making new highs a few days later," said Phil Flynn, analyst at Price Futures Group in Chicago.
"The problem is this time, after an extended sideways period, a confirmation of a breakdown would suggest that this market will need some major news to get us back on that long term bullish track."