Updated from 4:07 p.m. ESTStocks ended mixed Monday in thin preholiday trading, reacting to weak retail sales, Iraq worries and news that Citigroup ( C) will take a $1.5 billion charge to account for Friday's conflict-of-interest settlement. The Dow Jones Industrial Average ended down 18 points, or 0.2%, at 8493.29, while the Nasdaq finished up 18 points, or 1.4%, at 1381.68. The S&P 500 inched up 2 points, or 0.2%, to 1381.68. Volume on the New York Stock Exchange and the Nasdaq was very thin, and all three indices stayed in a tight trading range. Financial services giant Citigroup ( C), a Dow component, said it will take a fourth-quarter charge to reflect the equity research settlement and the negative impact bankrupt energy trader Enron.. On Friday, a number of Wall Street brokerages agreed to pay $1.4 billion to settle charges that they intentionally misled investors in order to secure sweeter investment-banking deals. "The settlement-in-principle, once finalized, will bring to a close a difficult chapter in our history," said Sanford Weill, Citigroup's chairman and chief executive, in a prepared statement. Citigroup fell 1.2% to $37.68. Elsewhere in financials, Bank of America ( BAC) said it will take a $1.2 billion charge in the fourth quarter for loan losses and net charge-offs, much higher than in previous quarters. The charges come because of the bank's exposure to the US Airways and UAL bankruptcies and the weak utilities market. Bank of America shares dropped 0.3% at $70.11. Technology stocks drew a measure of strength from an acquisition in the Internet space. On Monday, Yahoo! ( YHOO) announced that it bought Inktomi ( INKT) for $235 million in cash and debt, or $1.65 a share, which is a more than 40% premium from where Inktomi closed on Friday. Yahoo rose 3.8% to $17.73, while Inktomi added 36.8% to $1.60. Meanwhile, Wal-Mart ( WMT), the world's largest retailer, said December same-store sales are tracking at the low end of its 3% to 5% growth range. The company remains confident, however, that last-minute shoppers will come out of the woodwork to bridge the gap. Wal-Mart dropped 2.4% to $49.59. Federated Department Stores, which operates Macy's and Bloomingdale's, also warned that holiday sales would likely not meet expectations of flat to 2.5% growth for the period ending Jan. 4. Federated dropped 3.5% to $27.91. Consumer electronics retailer Tweeter Home Entertainment ( TWTR) warned that first-quarter earnings would fall well short of analysts' expectations, citing weaker-than-expected holiday sales. The company said it expects to earn 20 cents to 25 cents a share in the period ending Dec. 31, while Wall Street was looking for a net profit of 58 cents, according to Thomson Financial/First Call. Tweeter's shares fell 33% to $5.35. Rivals were feeling the heat, with Circuit City ( CC) off 4.5% to $7.18 and Best Buy ( BBY) down 3.2% to $23.97. Energizer ( ENR) announced that first-quarter earnings would come in between 89 cents and 92 cents a share excluding all items, which is slightly above Wall Street consensus of 90 cents a share. Energizer stock, which was spun off from Ralston Purina in 2000, rose 8% to $27.25.