The Dow industrials eked out a slim gain to close at a new record high today but the Nasdaq was unable to hold onto the 4,000 mark that it reached for the first time in 13 years as it retreated just below that level, despite gaining ground for the day. The S&P 500 Index fell short of break even today. The Dow rose 7.77 points to close at16,072.50, notching a gain of .05%. The Nasdaq finished trading at 3,994.57, up 2.92 points to advance .07%, while the S&P 500 ended the day at 1,802.48, down 2.28 points to dip .13%. Wal-Mart Stores Inc. (WMT) was among the Dow’s best performers as its shares rose 0.8 percent to close at $80.43, off an all-time intraday high of $80.57 after the world’s largest retailer announced it has chosen its next chief executive. Energy stocks slipped after the announcement of a deal to reduce sanctions on oil producing-nation Iran. The S&P energy sector index (SPNY) fell 0.8 percent, with social media shares also dropping. Volume is expected to remain low this week, with the U.S. Thanksgiving holiday on Thursday. “Retailers are taking focus this week. Black Friday is coming up, so there will be obviously some positioning ahead,” said Dennis Dick, proprietary trader at Bright Trading LLC in Las Vegas, referring to the day after Thanksgiving that is regarded as the start of the holiday shopping season.