华尔街的圣诞上冲规律
不少人说，圣诞老人带给人类的不仅仅是孩子喜爱的礼物，还有短期的牛市行情。
马上就是圣诞节了。美国的股市会不会再次受惠于圣诞老人而继续上涨呢？
下面这篇文章试图回答这个问题。
实际上，股市的上升和下降，与很多因素有关：已经上升了多少，基本面的改变和股价的改变之间的关系，市场对股票需求的变化等等。
一般来说，在新年开始时，由于很多人会增加在退休基金计划上的投资，对于股票的需求会有所增加，于是，就有可能拉动股市的价格。
不过，如果从历史角度看，这种可能性又会有多大呢？
再者，这种历史角度对于股市投资又到底有多少意义呢？
所谓“历史角度”，就是基于对历史数据的统计分析所获得的结果。这种结果对于具体时段的投资实际上没有多大的意义。
下面的文章也说，即使按照历史数据看，六月份的上涨甚至超过12月圣诞老人带来的上涨。
不管结果怎么样，大家看看开开心也好。
投资制胜的关键，一在心态，二在用心。
顺便说一句，前天晚上，那位大名鼎鼎的Mad Money家伙Jim Cramer在大吼推荐花旗银行！你信不信？
【附录】Is a Santa Claus rally coming to town?
If a market surge occurs this month, it most likely will be tucked under the tree with a 'do not open until Christmas' sign.
By Mark Hulbert, MarketWatch ，12/11/2009
Will the real Santa Claus rally please stand up?
I ask because, even though lots of advisers refer to something called a Santa Claus rally, there is little agreement on what, exactly, it involves.
A cynic might suspect these advisers are simply exploiting Santa's good name to justify whatever positive forecast they might otherwise have for December. But, surely, advisers wouldn't be so shameless to do that, would they?
Consider the range of meanings that I have found advisers give to the term "Santa Claus rally":
1. At some point during December, the stock market rallies.
2. The entire month of December tends to be a good one for the stock market.
3. The stock market performs particularly well starting around Christmas and lasting until the beginning of the new year.
And these were the meanings that I gleaned from just a cursory review of the advisers I monitor and of the financial news media. I'm sure more meanings would emerge if I spent more time looking, but you get the idea.
Do any of these definitions have strong support in the historical record?
Santa's track record
To find out, I examined the Dow Jones Industrial Average ($INDU) back to 1896, when it was created.
It turns out that the first definition -- that the stock market will rally at some point during December -- is true but pointless, since the stock market rallies during every period of the year. There has never been any month of the calendar in which the stock market didn't at some point stage a rally.
Consider next the second definition that some give to a Santa Claus rally: the notion that December as a whole is a particularly strong month for the stock market. At first blush the evidence for this proposition would appear to be strong. The average return for all non-December months since 1896, for example, is 0.5%. For Decembers, the average return is 1.4%.
But there is less here than meets the eye. It turns out that, though December's average is better than that of other months, June and July have even better average returns than December does. When ranked according to average returns, December is in third place.
Furthermore, there is not much consistency to December's return from year to year. In fact, December, on average, was one of the worst-performing months during several of the decades in the early part of the previous century. A year ago, the Dow lost 0.6% during December.
This volatility in December's year-to-year returns greatly reduces, if not eliminates, any statistical confidence one can have that December will be a good month for the stock market. In fact, several years ago, after subjecting the Dow's monthly returns to a number of complex statistical tests, two finance professors concluded that "it seems that there is no consistent monthly pattern in the stock market."
Wait until Christmas
One of the professors' related findings is that the primary source of December's apparent strength in the historical record comes from the period after Christmas through the end of the year. This period corresponds to two seasonal patterns that have been well-documented in other contexts: the so-called turn-of-the-month and turn-of-the-year effects.
So the third of the three definitions of a Santa Claus rally does have strong historical support. But notice carefully what this means: The Santa Claus rally that really exists does not arrive until Christmas is upon us.
Just like the man himself.
