Nomura Holdings has been benefiting from volatile global markets and a boom in investing and dealmaking at home, but the coming quarters may provide a test for the firm as the Iran war puts a strain on the global economy. | BLOOMBERG Nomura Holdings shares fell after its fourth-quarter profit missed analysts’ estimates, due to writedowns and a loss in Europe. The results released after the market closed on Friday overshadowed a second straight year of record earnings for Japan’s biggest brokerage. Impairments on its stakes in its research affiliate and a forestry company contrasted with otherwise solid results from its wealth management, trading and investment-banking operations. The shares slid as much as 6.5% in Tokyo on Monday morning, and are now down more than 4% this year, contrasting with the benchmark Topix’s 9.7% advance. Net income rose 2.7% from a year earlier to ¥73.9 billion ($463 million) in the three months ended March 31, missing analysts’ estimates for ¥98.9 billion.…