US stocks mostly edged up on Tuesday after ending last week at five-year highs, but gains were limited with investors showing caution as the earnings season picks up speed. Both the Dow and the Standard & Poor's 500 closed at five-year highs on Friday, boosted by better-than-expected results in the early part of the earnings season. Although major companies have issued bullish statements, many investors remain wary that economic uncertainty in the fourth quarter dented earnings and revenues. "The market is playing wait-and-see to see the way the earnings come in this week because you've got some biggies," said Fred Dickson, chief market strategist at D.A. Davidson & Co, in Lake Oswego, Oregon. Recent concerns about waning demand for Apple Inc products and a weak outlook from Intel Corp have diminished optimism about the tech sector's prospects. The S&P technology sector index, down 0.4 percent, was the worst performing of the 10 major S&P 500 sectors on Tuesday. Major tech companies scheduled to report results after the market's close on Tuesday include Google Inc, International Business Machines and Texas Instruments. Tech bellwethers Apple and Microsoft Corp are also set to report earnings this week. "Any one of those, if there is a big surprise up or down, could shift the balance in the markets. So investors are being far more cautious than normal, especially with the market averages having broken out to five-year highs," Dickson said. The Dow Jones industrial average gained 31.32 points, or 0.23 percent, to 13,681.02. The Standard & Poor's 500 Index added 1.48 points, or 0.10 percent, to 1,487.46. The Nasdaq Composite Index slipped 4.42 points, or 0.14 percent, to 3,130.29. Four Dow components reported early on Tuesday, and three rose on the results. Insurer Travellers Cos was the standout, climbing 2.6 percent to $78.33 and giving the biggest boost to the Dow after the company forecast higher premiums across its business. DuPont, the largest US chemical company by market capitalisation, reported revenue that exceeded Wall Street's expectations, while Verizon Communications Inc also posted revenue that beat forecasts. Shares of DuPont shot up 1.6 percent to $47.75 while Verizon's stock rose 0.9 percent to $42.94. On the downside, shares of Johnson & Johnson, the diversified health company, slipped 0.6 percent to $72.79 after the Dow component forecast 2013 earnings below expectations. According to Thomson Reuters data through Tuesday morning, of the 74 companies in the S&P 500 that have reported earnings so far, 62.2 percent have topped expectations, roughly even with the 62 percent average since 1994, but below the 65 percent average over the past four quarters. Overall, S&P 500 fourth-quarter earnings are forecast to have risen 2.6 percent. That estimate is above the 1.9 percent forecast from the start of earnings season, but well below the 9.9 percent fourth-quarter earnings forecast from October 1, the data showed. Economic data from the National Association of Realtors showed existing-home sales unexpectedly fell 1 percent in December, which was below expectations, but not a big enough dip to suggest the housing market's recovery may be in jeopardy. Republican leaders in the US House of Representatives said they aim on Wednesday to pass a nearly four-month extension of the US debt limit, allowing the government to borrow enough to meet its obligations during that period. Markets have recently been pressured by uncertainty stemming from Washington about the federal debt limit and spending cuts that could hamper US growth. US-listed shares of Research in Motion jumped 9.6 percent to $17.36 a day after its chief executive said the Canadian company may consider strategic alliances with other companies after the launch of devices powered by RIM's new BlackBerry 10 operating system.