After a stellar start to the year, it was bound to happen. The three main indexes on Wall Street each ended the week with a loss on Friday amid a disheartening euro debt picture.  Many investors and analysts had expected a bout of selling after the last several weeks of gains. The Standard & Poor’s 500-stock index had risen in each of the five weeks since the start of the year, and on Thursday the Dow Jones industrial average had its highest close since May 19, 2008, before the financial crisis.  But by the end of this week, doubts about the euro zone debt crisis — an entrenched theme of 2011 — resurfaced to bully the major market indexes lower. A general strike, protests and political turmoil boiled over in Greece a day after the government reached a provisional deal on the terms of a new loan program.  At the close on Friday, the day proved to be the worst trading session for the Dow so far this year. It finished down 0.69 percent, or 89.23 points at 12,801.23, making it the biggest drop by both measures for the index since Dec. 28.  The S.& P. was down 9.31 points, or also 0.69 percent, at 1,342.64. And the Nasdaq finished lower by 23.35 points, or 0.80 percent, at 2,903.88.  That meant the S.& P., the broader measure of the equity markets, had shaved off 0.2 percent over the five-day period, which was its first declining week in 2012. The Nasdaq ended the week down 0.06 percent, also its first week lower in 2012. The Dow Jones industrial average finished lower by 0.5 percent in the week, its second week down this year.  Alan B. Lancz, the president of the money management and investment advisory firm Alan B. Lancz & Associates, said the market was overbought in the last few weeks and was due for a pullback.  “It’s been an incredible stretch,” he said, referring to the gains since the beginning of the year. “But I think the markets are a little bit ahead of themselves, and that is what we are seeing here.”  With uncertainties about Greece, new fears about inflation in China and worries about tepid growth in the United States, he said, “Nobody wants to hold over the weekend.”  The last time the S.& P. 500 had a weekly loss was the final week of 2011, when it ended down 0.6 percent.  Still, the markets have seen little of the volatile trading that characterized the financial markets last year, when there were often swings of more than 2 percent in one day.  Keith B. Hembre, the chief economist and chief investment strategist at Nuveen Asset Management, said the declines on Friday were not necessarily signs of a trend and meant only that “there are risks in the world today.”  He added that the declines on Friday reflected fears of contagion should Greece default on a bond redemption due in March.  “You get the whole financial contagion process moving forward with a lot more uncertainty, a lot more risk aversion in the near term,” he said.  Financial stocks, which have traditionally been sensitive to the turmoil in the euro zone, were down by 1 percent. Bank of America was down 1.34 percent at $8.07. Citigroup fell 2.2 percent to $32.92. Energy and materials were also lower by 1 percent or more.  Interest rates were lower. The Treasury’s benchmark 10-year note rose 15/32, to 100 5/32, and the yield fell to 1.98 percent from 2.04 percent late Thursday.  In Europe, the Euro Stoxx 50 index, a barometer of euro zone blue chips, closed down 1.7 percent, and the FTSE 100 index in London fell 0.7 percent. The DAX index in Germany was lower by 1.4 percent. Indexes were also lower in France, Italy and Spain.  The euro closed down slightly at 1.3172, from 1.3283.
Political tussling over the long-awaited Greek debt deal led to a day of sharp declines on Wall Street and the S.& P. 500âs first weekly loss this year.