U.S. stocks dropped significantly Monday, with the Standard & Poor's 500 posting its biggest decline in two months. The Dow Jones industrial average fell 268.37, or 1 percent, to 27,783.04. The broader S&P 500 index fell 27.11, or 0.9 percent, to 3,113.87. The technology-heavy Nasdaq composite index fell 97.48, or 1.1 percent, to 8,567.99.