Crude oil price slumped on concerns over supply glut. A Reuters survey indicated that OPEC production rose in May, as Nigeria and Libya raised output. These two countries are exempted from the output cut deal. It was estimated that Libya production rose to a fresh 3-year high of 0.83M bpd last month. The front-month WTI crude oil contract plunged to a 3-week low of 47.73 before settling at 48.32, down -2.7%, while the Brent contract slumped to 50.31 at close, down -2.95%.