CNBC | Oil prices are heading into what has been an ugly part of the year CNBC Oil prices were on a tear in the third quarter, but are heading into a typically weak period for the commodity. In the last 25 years, U.S. crude traded positive 40 percent of the time in the fourth quarter with an average return of -7.5 percent ... Oil falls as data show decline in OPEC output-cut compliance Oil slips as higher OPEC output halts rally Oil Falls on Production Surge |