According to stock market statisticians, the S&P 500 stock index historically makes an average of 1.3 to 1.4 percent gains during the last five days of December and the first two days of January. The so-called Santa Clause rally has happened nearly 80 percent of the time, with analysts attributing the shift to seasonal enthusiasm, lower volume and more retail investor influence. The rally is also said to coincide with a positive market outcome in the coming year, with a market downturn over the holiday also predicting the coming year.  All three major stock indices closed down today and are trading negative thus far over this Christmas period. Conversely, the major banks and various investment shops are said to be optimistic that t...