For much of the past year, oil prices were headed in one direction: down. With output swelling from the shale-oil boom, the U.S. benchmark fell 59% from its 2014 high last June to its low on March 17. But then came a sudden reversal. Amid concerns about the impact of low prices on supply, oil prices in April posted their biggest monthly gains in about six years. So, where are oil prices headed next? A lot is riding on the answer. Oil prices have a profound impact on everything from the health of the global economy to international relations, from the fate of energy companies to the pocketbooks of individuals. Cheap oil, for instance, has been a boon to consumers around the world, but sustained low prices […]