Santa Claus rally
n.— «Stocks have lost ground since the Dow rose 19.6 percent from late November to the first part of 2009—a year-end advance often referred to as a Santa Claus rally.» —“Stocks tumble as oil falls on economic worries” by Sara Lepro, Tim Paradis Associated Press Jan. 12, 2009. (source: Double-Tongued Dictionary)