The dollar rose against other world currencies, hitting slightly below $1.49 against the euro. Treasury prices fell as yields rose. Oil fell slightly to $76.72 a barrel, contributing to declines in energy stocks. Gold climbed to $1,150 an ounce even as the dollar gained strength, a trend analysts attributed to speculation that the dollar would continue to weaken.  Worries over the strength of the underlying economy seemed to make investors cautious, leaving some analysts wondering whether a remarkable eight-month rally might be showing signs of retreat.  Joseph Saluzzi, co-head of equity trading at Themis Trading, noted that while the number of shares trading hands on Wall Street was up from a year ago, much of the activity could be attributed to high-frequency traders, not longer-term investors.  “We have a market that is propped up on hope and short-term-type trading,” Mr. Saluzzi said. “Once investors start to lose confidence, and people realize you’re not necessarily going to see a vibrant economy soon, this could unravel quickly.”  He noted, however, that the market had been extremely volatile recently. “We’ve seen market character change a few times, only to change and run right back up,” he added.  But Carmine Grigoli, chief investment strategist at Mizuho Securities USA, said there was little evidence that the stock market had turned overly optimistic.  “We have yet to see the widespread optimism and the high levels of public participation characteristic of a speculative market,” he wrote in a research note on Friday. “In fact, the public remains remarkably uninvolved and skeptical about the bull market.”  Technology stocks declined as investors began to doubt whether 2010 profits would meet expectations. David G. Dietze, president and chief investment strategist at Point View Financial Services, said investors flocked to technology stocks in recent months because those stocks tended to be globally diversified and insulated from the booms and busts of particular countries.  “There has been a fabulous run,” Mr. Dietze said. “Now these earnings estimates are making investors think maybe the market has pushed these stocks too far too fast.”  He said concern over the fundamental health of the economy was also driving stocks lower, pointing to news on Friday that D. R. Horton, the home builder, projected a dim outlook for the housing market. Shares of D. R. Horton fell more than 15 percent, closing at $10.38.  In addition, the president of the European Central Bank, Jean-Claude Trichet, signaled that it might be time for policy makers across the world to gradually reduce injections of emergency cash into struggling economies.  “Emergency treatment and strong medicines are sometimes necessary, but if their use is prolonged, they can lead to dependence and even addiction,” Mr. Trichet said, according to Reuters.  An odd quirk of the markets startled some traders on Friday, as the yield on three-month Treasury bills briefly turned slightly negative. It hovered near zero for most of the day.  On Thursday, the yield slipped below zero for the first time since the height of the financial crisis in 2008. The negative yield last year was a sign of desperation as investors rushed to a haven in Treasury bills, in effect paying to keep money secure.  The Treasury’s benchmark 10-year note fell 8/32, to 100 2/32, and the yield rose to 3.37 percent from 3.34 percent.  Overseas, Japan’s Nikkei stock average closed down 0.5 percent. Britain’s FTSE 100 fell 0.3 percent, Germany’s DAX index declined 0.7 percent and France’s CAC-40 dropped 0.8 percent.  A version of this article appears in print on November 21, 2009, on Page B6 of the New York edition with the headline: Shares Finish Lower on Doubts About Recovery. Order Reprints| Today's Paper|Subscribe
Investors are increasingly wondering about the speed of the economy recovery and they are questioning the fast-paced rise of technology stocks.