*********
集中投資？還是分散投資？此問題經常困擾投資人。價值投資就一定要集中投資嗎？巴菲特的著名文章：超級投資人(The Super Investors of Graham-and-Doddsville)(註一)可能可以為你解惑，建議投資人細心研讀這篇極具啟發性的文章，可以一窺巴菲特價值投資思想的精華。
註一：此文為巴菲特1984年為了紀念其恩師Benjamin Graham與David Dodd合著的證券分析(Security Analysis)出版滿五十週年紀念而在母校哥倫比亞大學所做的專題演講。讀者可在智慧型投資人(Intelligent Investor)這本書的附錄找到這篇文章。
有本書叫「The Warren Buffett Portfolio」﹐該書強調了集中投資的好處，也舉了許多巴菲特的投資實例說明，因此很容易讓讀者得到一個印象，以為實踐價值投資就非要集中投資不可。這可能是很多學習價值 投資的投資人所得到的看法。沒錯，巴菲特自己是集中投資概念的忠實擁護者，但他並沒說價值投資只能集中投資，或認為分散投資就非價值投資。對大部分想實踐價值投資的投資人來說，集中投資可能是比較容易的方式，因為一般投資人能花的時間及精力有限，只能深入了解少數幾家公司，這也是巴菲特大力推薦集中投資的理由。
因為你越了解一家公司的經營管理，越能估計出未來的現金流量以及達成的機率，因而估算出來的企業價值也就更確定，風險自然會小很多，這也是價值投資所強調的精神：風險低、報酬高。
但這並不排除有些價值投資人反其道而行，採取大量分散投資的方法。
為什麼呢？
其實，答案很簡單：價值投資無關乎集中或分散。
價值投資的真諦只有一個：用五毛買一塊。至於你如何估計出一塊錢的價值、在估算企業價值時如何選定折現率、或是你用什麼方法找到「用五毛買一塊」的機會，都是因人而異，八仙過海、各顯神通。
巴菲特在文中(The Superinvestors of Graham-and-Doddsville)特別舉出兩個極端相反的例子：Walter Schloss與Charlie Munger。
Schloss沒唸過大學，只上過Ben Graham的夜間投資課程。他從不看一般報導的資訊，只看類似Moody手冊提供的數字，以及要求公司寄年報給他。他的投資組合極為分散，擁有的股票超過一百支。但他了解如何選股：價格遠低於價值，如此而已。他相信只要公司價值一美元而能用40美分買進，遲早會獲利。他不太關心公司的本質，也不關心是否總統大選年度。他的投資績效如下：
1956-1983第一季(28.25年)
S&P 500(含股息) 8.4%
Walter Schloss Partnership 21.3%
另一極端則是Munger。畢業於哈佛，是執業律師。他的投資組合極為集中--剛巧他也是精神極為集中的人，年度投資報酬績效的變動比較激烈，但他也是依照相同的原則選股：價格遠低於價值。他的投資績效如下所示：
1962-1975
Dow 30 5.0%
Charlie Munger Partnership 19.8%
他 們的投資績效都遠遠超過S&P500或Dow 30兩大指數，兩人的主要差異在於年度投資報酬績效的波動幅度。Schloss因為投資組合極度分散而Munger則為極度集中，因此可以推論出 Schloss的年度投資報酬績效的波動會比Munger小很多，而事實上也的確如此。（請參看原文中的投資績效表一與表五。）
巴菲特在該文中舉出的九個實例都是忠心的價值投資實踐者，他們只有一個共通的地方---只關心兩個變數：價格與價值。至於投資組合是否要集中或分散，要投資那些行業或公司，甚至投資經理是否應該擁有大學學位，這些都不是重點。
許多投資人也許看過巴菲特這篇文章，但大部分人可能就是匆匆看過一遍，沒有仔細體會巴菲特想要傳達的意思。除了前面提到的價值與價格、集中與分散外，巴菲特在文中還提到了幾個重要的觀念：
- 要以買整個企業的心態來買股票，而非僅是買賣股票。
- 風險與報酬
- 投資人必須要能估算一家企業的約略價值。
- 安全邊際
建議投資人重新仔細研讀這篇文章。巴菲特很少說廢話，更少執筆寫文章，因此他親自執筆所寫的文章都是經過深刻思索、仔細過濾後的精髓。這篇文章雖然很短，但基本上已涵蓋了巴菲特價值投資思想的精華，讀者千萬不要輕易掠過一遍就算了。
The Superinvestors of Graham-and-Doddsville by Warren E. Buffett
Is the Graham and Dodd "look for values with a significant margin of safety relative to prices" approach to security analysis out of date? Many of the professors who write textbooks today say yes. They argue that the stock market is efficient; that is, that stock prices reflect everything that is known about a company's prospects and about the state of the economy.There are no undervalued stocks, these theorists argue, because there are smart security analysts who utilize all available information to ensure unfailingly appropriate prices. Investors who seem to beat the market year after year are just lucky. "If prices fully reflect available information, this sort of investment adeptness is ruled out," writes one of today's textbook authors.
Well, maybe. But I want to present to you a group of investors who have, year in and year out, beaten the Standard & Poor's 500 stock index. The hypothesis that they do this by pure chance is at least worth examining. Crucial to this examination is the fact that these winners were all well known to me and pre-identified as superior investors, the most recent identification occurring over fifteen years ago. Absent this condition - that is, if I had just recently searched among thousands of records to select a few names for you this morning -- I would advise you to stop reading right here. I should add that all of these records have been audited. And I should further add that I have known many of those who have invested with these managers, and the checks received by those participants over the years have matched the stated records.
Before we begin this examination, I would like you to imagine a national coin-flipping contest. Let's assume we get 225 million Americans up tomorrow morning and we ask them all to wager a dollar. They go out in the morning at sunrise, and they all call the flip of a coin. If they call correctly, they win a dollar from those who called wrong. Each day the losers drop out, and on the subsequent day the stakes build as all previous winnings are put on the line. After ten flips on ten mornings, there will be approximately 220,000 people in the United States who have correctly called ten flips in a row. They each will have won a little over $1,000.
Now this group will probably start getting a little puffed up about this, human nature being what it is. They may try to be modest, but at cocktail parties they will occasionally admit to attractive members of the opposite sex what their technique is, and what marvelous insights they bring to the field of flipping.
Assuming that the winners are getting the appropriate rewards from the losers, in another ten days we will have 215 people who have successfully called their coin flips 20 times in a row and who, by this exercise, each have turned one dollar into a little over $1 million. $225 million would have been lost, $225 million would have been won.
By then, this group will really lose their heads. They will probably write books on "How I turned a Dollar into a Million in Twenty Days Working Thirty Seconds a Morning." Worse yet, they'll probably start jetting around the country attending seminars on efficient coin-flipping and tackling skeptical professors with, " If it can't be done, why are there 215 of us?"
By then some business school professor will probably be rude enough to bring up the fact that if 225 million orangutans had engaged in a similar exercise, the results would be much the same - 215 egotistical orangutans with 20 straight winning flips.
Would argue, however, that there are some important differences in the examples I am going to present. For one thing, if (a) you had taken 225 million orangutans distributed roughly as the U.S. population is; if (b) 215 winners were left after 20 days; and if (c) you found that 40 came from a particular zoo in Omaha, you would be pretty sure you were on to something. So you would probably go out and ask the zookeeper about what he's feeding them, whether they had special exercises, what books they read, and who knows what else. That is, if you found any really extraordinary concentrations of success, you might want to see if you could identify concentrations of unusual characteristics that might be causal factors.
Scientific inquiry naturally follows such a pattern. If you were trying to analyze possible causes of a rare type of cancer -- with, say, 1,500 cases a year in the United States -- and you found that 400 of them occurred in some little mining town in Montana, you would get very interested in the water there, or the occupation of those afflicted, or other variables. You know it's not random chance that 400 come from a small area. You would not necessarily know the causal factors, but you would know where to search.
I submit to you that there are ways of defining an origin other than geography. In addition to geographical origins, there can be what I call an intellectual origin. I think you will find that a disproportionate number of successful coin-flippers in the investment world came from a very small intellectual village that could be called Graham-and-Doddsville. A concentration of winners that simply cannot be explained by chance can be traced to this particular intellectual village.
Conditions could exist that would make even that concentration unimportant. Perhaps 100 people were simply imitating the coin-flipping call of some terribly persuasive personality. When he called heads, 100 followers automatically called that coin the same way. If the leader was part of the 215 left at the end, the fact that 100 came from the same intellectual origin would mean nothing. You would simply be identifying one case as a hundred cases. Similarly, let's assume that you lived in a strongly patriarchal society and every family in the United States conveniently consisted of ten members. Further assume that the patriarchal culture was so strong that, when the 225 million people went out the first day, every member of the family identified with the father's call. Now, at the end of the 20-day period, you would have 215 winners, and you would find that they came from only 21.5 families. Some naive types might say that this indicates an enormous hereditary factor as an explanation of successful coin-flipping. But, of course, it would have no significance at all because it would simply mean that you didn't have 215 individual winners, but rather 21.5 randomly distributed families who were winners.
In this group of successful investors that I want to consider, there has been a common intellectual patriarch, Ben Graham. But the children who left the house of this intellectual patriarch have called their "flips" in very different ways. They have gone to different places and bought and sold different stocks and companies, yet they have had a combined record that simply cannot be explained by the fact that they are all calling flips identically because a leader is signaling the calls for them to make. The patriarch has merely set forth the intellectual theory for making coin-calling decisions, but each student has decided on his own manner of applying the theory.
The common intellectual theme of the investors from Graham-and-Doddsville is this: they search for discrepancies between the value of a business and the price of small pieces of that business in the market. Essentially, they exploit those discrepancies without the efficient market theorist's concern as to whether the stocks are bought on Monday or Thursday, or whether it is January or July, etc. Incidentally, when businessmen buy businesses, which is just what our Graham & Dodd investors are doing through the purchase of marketable stocks -- I doubt that many are cranking into their purchase decision the day of the week or the month in which the transaction is going to occur. If it doesn't make any difference whether all of a business is being bought on a Monday or a Friday, I am baffled why academicians invest extensive time and effort to see whether it makes a difference when buying small pieces of those same businesses. Our Graham & Dodd investors, needless to say, do not discuss beta, the capital asset pricing model, or covariance in returns among securities. These are not subjects of any interest to them. In fact, most of them would have difficulty defining those terms. The investors simply focus on two variables: price and value.
I always find it extraordinary that so many studies are made of price and volume behavior, the stuff of chartists. Can you imagine buying an entire business simply because the price of the business had been marked up substantially last week and the week before? Of course, the reason a lot of studies are made of these price and volume variables is that now, in the age of computers, there are almost endless data available about them. It isn't necessarily because such studies have any utility; it's simply that the data are there and academicians have [worked] hard to learn the mathematical skills needed to manipulate them. Once these skills are acquired, it seems sinful not to use them, even if the usage has no utility or negative utility. As a friend said, to a man with a hammer, everything looks like a nail.
I think the group that we have identified by a common intellectual home is worthy of study. Incidentally, despite all the academic studies of the influence of such variables as price, volume, seasonality, capitalization size, etc., upon stock performance, no interest has been evidenced in studying the methods of this unusual concentration of value-oriented winners.
I begin this study of results by going back to a group of four of us who worked at Graham-Newman Corporation from 1954 through 1956. There were only four -- I have not selected these names from among thousands. I offered to go to work at Graham-Newman for nothing after I took Ben Graham's class, but he turned me down as overvalued. He took this value stuff very seriously! After much pestering he finally hired me. There were three partners and four of us as the "peasant" level. All four left between 1955 and 1957 when the firm was wound up, and it's possible to trace the record of three.
No comments:
Post a Comment