Traders work on the floor of the New York Stock Exchange (NYSE) on May 6, 2026 in New York City. Spencer Platt | Getty Images The Iran war has triggered big swings in the stock market since the conflict started more than two months ago. While sharp selloffs in stocks can be unsettling, they offer a silver lining to investors, financial advisors and other experts said. "Every drawdown is a useful stress test," Kevin Khang, senior global economist at Vanguard Group, an asset manager, wrote in an April 22 market commentary . Namely, the "discomfort" that investors feel reveals important information about their risk tolerances — something that "a calm market simply does not provide," Khang wrote. That information can help guide investors' overall mix of stocks, bonds and other financial assets in a portfolio.…