Dow, S&P hit record closing highs on greater risk tolerance

By Sam Forgione NEW YORK (Reuters) - The benchmark U.S. S&P 500 stock index set record closing and intraday highs for the second straight day on Tuesday and the Dow Jones industrial average reached record highs for the first time in over a year as optimism about the world economy and upbeat corporate results from Alcoa boosted risk appetite. The benchmark S&P 500 ended at 2,152.14, topping Monday's record close of 2,137.16, while the Dow closed at 18,347.67 to top its previous record hig