The Santa Claus rally is a gift for investors, but it doesn't happen every year. Read on to learn more about the whens and whys of this phenomenon.

Since 1950, the S&P 500 has, on average, returned 1.4% in January and 10.4% in the calendar year after a Santa Claus rally, according to a recent analysis by LPL Financial.

Tesla's current momentum, surging optimism and groundbreaking developments create an ideal setup for a Santa Claus Rally. TSLA Trades Above 50 & 200-Day SMA Image Source: Zacks Investment Research ...

The Santa Claus trading window starts December 24 and should bring a stock market rally this year. Historically, the S&P 500 gains 1.3% during this seven-day period and is positive 79% of the time.

The average gain during the Santa Claus trading window is even stronger, at 1.6%, when including stock returns going back to 1928, according to data from Bank of America. Here's where US indexes ...

The Santa Claus trading window starts December 24 and should bring a stock market rally this year. Historically, the S&P 500 gains 1.3% during this seven-day period and is positive 79% of the time.

Santa Claus gestures on the floor at the closing bell of the Dow Industrial Average at the New York Stock Exchange BRYAN R. SMITH/AFP via Getty Images US stocks rose in a shortened holiday trading ...