Iran war volatility strains trading in world's biggest markets https://www.reuters.com/business/finance/global-markets-trading-analysis-pix-2026-03-30/?taid=69ca393f1de6e000018af12e https://www.reuters.com/business/finance/global-markets-trading-analysis-pix-2026-03-30/?taid=69ca393f1de6e000018af12e