"A Santa Claus rally is a rise in stock prices in the month of December, generally seen over the final week of trading prior to the new year. The rally is generally attributed to anticipation of the January effect, an injection of additional funds into the market, and to additional trades which must, for accounting and tax reasons, be completed by the end of the year. Another reason for the rally may be fund managers "window dressing" their holdings with stocks that have performed well."/Wikipedia/ .
Is it true?
In my opinion, Santa Claus Rally always starts from the Autumn Bottom (usually in October). This wave takes about a month. Then we get the correction (in most cases in November) and the last move up to the end of December. Often, this wave is a extended by the January Effect ( up to the February correction).
After all, Santa Claus has two legs...