The S&P 500 edged up to a five-year high Tuesday, but stocks finished narrowly mixed after a session with no dominant news. The benchmark index added nearly 0.2%, while the NYSE composite rose 0.4%. The Nasdaq fell a little less than 0.2%. So far this week, the market has displayed muted action while drawing relatively light volume, as the S&P 500 and Nasdaq digest their six-week winning streaks. On Tuesday, volume increased on both main