    Sentence 1: The Standard & Poor's 500 stock index  lended the quarter up 120 points , a gain of 14 percent ,  the best performance for that broad market benchmark  isince 1998 .    Sentence 2: The Standard and Poor 's 500-stock index ,  fa broad collection of equities representing leading  companies “finished its best quarter yesterday since  ithe last three months of 1998 .