Major U.S. equity indices showed gains on May 26, 2026, following the Memorial Day closure, with the S&P 500 and Nasdaq reaching new all-time highs while the Dow Jones edged lower. Micron Technology shares rose nearly 20 percent, pushing its market capitalization above $1 trillion. Prior U.S. military strikes on Iran had lifted Brent crude prices, though market commentary cited optimism over potential negotiations.