New technology, high oil prices, and plentiful cheap credit have encouraged the boom. Some $200bn has been borrowed to invest in fracking in the last few years, accounting for 15 percent of the entire $1.3tr US junk bond market . Investors were, in effect, betting on continuing high oil prices making their investments profitable for years to come. Price Slump Last year’s slump in prices trashed that calculation. From a mid-year high of $115 per barrel, by the end of 2014 the price per barrel had fallen by more than 40 percent. More than half of US shale rigs have been laid up since October. The driver, last year, was the behaviour of OPEC – the Organization of Petroleum Exporting Countries. OPEC is a cartel agreement among major oil producers that seeks to manage the international market for oil. With oil prices already plunging over the summer, OPEC could […]