Hedge funds are betting that the rally in U.S. natural-gas prices won’t last. Money managers cut the combined net-long position across four benchmark contracts by 21 percent in the week ended Aug. 5, after 15 weeks of above-average stockpile increases. Bullish wagers retreated to an 18-month low even as futures traded in New York gained 2.3 percent in the report week, U.S. Commodity Futures Trading Commission data show. Goldman Sachs Group Inc. cut its price forecast last week as shale-gas production in the eastern U.S. surged to an all-time high. Power demand in June and July fell to five-year seasonal lows amid unusually cool weather from Texas to Boston , Edison Electric Institute data show. Gas futures have dropped 12 percent since the start of summer. “If you are a money manager and you see above-average storage injections week after week and a decline in price, selling is rational,” […]