Oil price volatility jumped to its highest level in more than four months on Thursday as U.S. crude plunged 5 percent, after data from the U.S. government showed inventories fell less than expected, disappointing market bulls worried about a glut of crude supply. The CBOE volatility index, a gauge of options premiums based on moves in the U.S. oil exchange traded fund , jumped from 41 to more than 58 - its highest level since March 2. U.S. crude futures closed the session down $2.29, or 4.8 percent, at $45.14 a barrel, having earlier hit a two-month low at $44.87. Resurgent output from across the world and uncertainty around the global economy after Britain's unexpected vote to exit the European Union have weighed on oil.