Caution Abounds, but Markets Aim Higher Wall Street edged modestly higher on Tuesday after a three-session decline on the Standard & Poor's 500, but market sentiment was weighed by an unexpected drop in durable good orders in December and disappointing iPhone sales at the tech giant Apple. The Dow Jones industrial average rose 0.34 percent, the S.&P. 500 gained 0.17 percent and the Nasdaq Composite dropped 0.21 percent after the markets opened. Investors were cautious as the Federal Reserve was set to begin its two-day policy meeting. Concerns have been growing about more withdrawal of United States monetary stimulus and slowing Chinese growth, which amplified country-specific political turmoil from Turkey to Thailand. Durable goods orders unexpectedly plunged in December, falling 4.3 percent compared with what analysts had expected to be an 1.8 percent increase. Technology stocks could fall after disappointing quarterly results from Apple. The stock opened 7.8 percent lower after iPhone sales in the holiday shopping season missed lofty expectations and the company forecast weak revenue for the current quarter. At least 12 brokerages lowered their price targets on Apple's shares, reflecting concerns that it was becoming harder to sell high-end phones as markets became saturated. The stock had gained a quarter of its value in the last six months. In other earnings, Pfizer reported better-than-expected fourth-quarter results, helped by sales of new treatments for cancer, nerve pain and arthritis, sending shares 3 percent higher after the opening. The New York-based hedge fund Casablanca Capital picked up a 5.2 percent stake in Cliffs Natural Resources and urged the iron ore producer to spin off international assets and double its annual dividend. The stock rose about 7 percent. The Conference Board's consumer confidence index for January was due later Tuesday. United States stocks extended recent losses on Monday, with the S.&P. 500 falling for a third straight session as concern grew about the Fed's plans for withdrawing stimulus. The losses, which picked up late in the session after the S.&P. 500 briefly traded in positive territory, followed a steep sell-off late last week tied to emerging market concerns. The slide gave the S.&P. 500 its worst weekly percentage loss since June 2012.