Markets continued to take out new highs, with the Dow closing over 18,000 for the first time ever. For the Trading Week Ahead, markets will be closed on Thursday, Jan 1, in observance of the New Year's Day. TheStreet's Jill Malandrino points out economic data will be light, but there are some key numbers to watch for in manufacturing, housing, jobs and consumer. No S&P 500 companies are scheduled to report and the only shareholder meeting of note is Walgreen on Monday. The commodity trade continues to take center stage and will remain in the spotlight for 2015, particularly crude and gold, especially with the U.S. dollar moving higher.