West Texas Intermediate futures for February delivery plunged to $32.94 (-3.03%), while Brent crude dropped to $33.09 (-3.33%) amid turmoil on Chinese stock markets and the ongoing global supply glut. Trading on Chinese stock markets was suspended twice this week. Today stocks lost around 7% in less than half an hour. Investors are concerned about economic growth in the world's second-biggest oil consumer.

Meanwhile the Energy Information Administration reported yesterday that U.S. crude oil stockpiles fell by 5.1 million barrels last week. However production remained above 9 million barrels a day, which is more than last year.