U.S. crude prices jumped more than 27 percent in three trading days between Thursday and Monday, which should convince even the most die-hard believers the oil futures market is neither efficient nor rational. The rally has left traders, analysts and journalists struggling to make sense of the sudden change in direction after prices had fallen steadily for two months, hitting their lowest level since 2009. Possible explanations range from a bounce in global stock markets, pipeline problems in Nigeria, new data showing U.S. oil production falling, and an editorial published in OPEC’s monthly bulletin interpreted by some analysts as a call for a coordinated approach to cutting output (“Cooperation holds the key to oil’s future”, August 2015). But it should be obvious none of these factors, singly or in combination, is sufficient to explain an increase in the […]