This week was one made for hackneyed phrases: "Santa didn't show"; "Investors got lumps of coal"; "Blue Christmas on Wall Street," etc. In other words, it was a disappointing week for those long stocks. Rather than experiencing any holiday cheer or the onset of the traditional year-end rally, this week saw the Dow Jones Industrial Average fall 2.4%, the S&P 500 shed 2.3% and the Nasdaq Composite slide 1.1%. "It's curious, everything that has become consensus is wrong," said John Roque, senior analyst at Arnhold & S. Bleichroeder. "Figure out what consensus is and fade it, that's the best thing to do." Roque, an occasional RealMoney.com contributor, referred specifically to hope for a "Santa Claus" rally, as well as expectations that robust consumer spending would salvage the holiday shopping season and make retailers good buys. Instead, retailing shares plummeted as industry giants Wal-Mart ( WMT) and Target ( TGT) as well as smaller players such as Tweeter Home Entertainment ( TWTR) and Ultimate Electronics ( ULTE) announced disappointing December sales and/or warned fourth-quarter results will not meet expectations. For the week, the S&P Retail Index fell 3.6%. Less obviously, while most traders "want to focus on the semis, the banks are ultimately the most important sector," Roque said, noting Citigroup ( C) was particularly weak Friday, when stock proxies suffered their worst declines of the week. Citigroup fell 2.4% Friday while the Dow fell 1.5%, the S&P shed 1.6% and the Comp slid 1.4%. (Major averages also ended Friday's session below their respective 50-day moving averages, a negative development according to devotees of technical analysis.) "Right here, Citigroup is the most important stock in the S&P 500," he said, suggesting the financial giant "has risk to $30," which means 850 is "fait accompli" for the S&P 500 and that 800 is quite possible in the near-to-intermediate term.