"Santa Claus tends to come to Wall Street nearly every year, bringing a short, sweet, respectable rally within the last five days of the year and the first two in January."
Average gain 1.6% since 1969 Average gain 1.5% since 1950. Page 112 of The Stock Trader's Almanac
The Almanac also says:
"If Santa Claus should fail to call, The bears may come to Broad & Wall"
Last five days of the year plus the first two in January (charts will build):