Stocks are falling in the opening moments of trading as investors show a little more caution after the market's huge two-week rally. Investors are following their counterparts overseas Tuesday in sending major indexes lower. Mixed earnings reports continued Tuesday morning as Viacom reported a sharp decline in profit and Valero Energy posted a quarterly loss. However, both results were slightly better than expectations. Investors are also awaiting a key report on consumer confidence is due out at 10 a.m. EDT (1400 GMT). The Dow Jones industrial average is down 41.04, or 0.5 percent, at 9,067.47. The Standard & Poor's 500 index is down 5.20, or 0.5 percent, at 976.98, while the Nasdaq composite index is down 8.67, or 0.4 percent, at 1,959.22. 