The S&P 500’s huge gains over the past two years won’t be duplicated some analysts say, as a series of economic challenges piles up. internal-storyline-no, Stocks and Bonds, Yardeni, Edward, Fink, Laurence D, Goldman Sachs Group Inc The S&P 500’s huge gains over the past two years won’t be duplicated some analysts say, as a series of economic challenges piles up. NYT > Business