The U.S. stock market opened lower on Monday as caution prevailed following a surprise drop in Chinese exports in February. Markets appeared on pause after a week of gains, which sent the benchmark S&P 500 into record territory on Friday. With no official data releases scheduled, investors will focus on two Federal Reserve officials' speeches. The S&P 500 opened 4.57 points, or 0.2%, lower at 1,873.22, hovering near its record levels. The Dow Jones Industrial Average opened down 45 points, or 0.3%, to 16,407.03. The Nasdaq Composite began the day 6.48 points, or 0.1%, lower at 4,330.3