The sun sets beyond an oil pumping unit at a drilling site operated by Tatneft OAO near Almetyevsk, Russia. The ruble climbed from the weakest level since February as oil rebounded and Citigroup Inc. raised its recommendation on Russia’s currency, saying the slump was “excessive.” The ruble strengthened 0.5 percent to 63.1770 against the dollar by 5:26 p.m. in Moscow after slipping 10 percent in July, the biggest drop among major global currencies. Crude oil, which tumbled into a bear market last month, rose 1.3 percent to $50.17 a barrel in London. The Bank of Russia was forced last week to halt its daily dollar purchases after the ruble retreated with oil to the lowest levels in six months. There are signs the drop may have gone too far: the ruble’s 14-day relative strength index fell to 21.1 yesterday, the lowest since Dec. 16 and below the level of […]