"Right now OPEC's strategy is working: They're retaining and regaining that market share they lost over the course of 2014 when non-OPEC suppliers raised their output when prices were extremely high," he said.
About last week's oil rally, Cohen did say that "the strength we have seen so far is something that we have to acknowledge when we put together our price forecast for the next couple months."
Oil prices rose in a volatile day of trading on Monday as concerns over tension in the Middle East and a drop in the number of U.S. rigs drilling for crude offset comments from Saudi Arabia's oil minister that Saudi production would stay near record levels in April.
Saudi Arabia has put security forces on alert for a possible militant attack on a shopping mall or energy installation, Interior Ministry spokesman Mansour Turki said on Monday.
Read MoreFor crude oil, this looks like 2009 all over again
Since the beginning of April, oil prices have risen around 17 percent, pushed up by reports of a possible dip in U.S. output.