U.S. stocks were mixed on Tuesday as Federal Reserve policymakers kicked off a two-day interest rate meeting and investors braced for quarterly results of the technology companies. The Dow Jones industrial average fell 19.31, or 0.11 percent, to 18,473.75. The broader Standard & Poor's 500 index climbed 0.70, or 0.03 percent, to 2,169.18. The technology-heavy Nasdaq composite index increased 12.42, or 0.24 percent, to 5,110.05.