How to Spread Your Market Bets
It's a weighty issue.
How should you divvy up your portfolio among large stocks, small companies, foreign shares, bonds and other market sectors?
Whenever I get this question, my first instinct is to consider the collective judgment of investors, as reflected in each sector's total market value. After all, these market weights tell us how investors, as a group, have chosen to divide up their money.
Yet, in all likelihood, your portfolio will end up looking nothing like these market weights. Trying to put together the right investment mix? Here's when market weights are -- and aren't -- useful.
Taking Stock
Suppose you are trying to figure out how to divide your U.S. stock portfolio between large-company and small-company stock mutual funds. To my mind, this is when market values are most useful.
Today, the big blue-chip stocks in the Standard & Poor's 500-stock index account for roughly three-quarters of the U.S. stock market's total value, with the other quarter taken up by small and midsize companies, according to Vanguard Group in Malvern, Pa.
That doesn't mean you should necessarily split your U.S. stock portfolio that way. Instead, you might decide, say, to overweight smaller companies. Even then, however, it is worth considering market values, so you can gauge just how big a bet you are making.
Many investors like to divide up their U.S. stock portfolio even further, by splitting their money between growth and value funds. Growth funds buy stocks with rapid sales and earnings growth, while value funds favor shares that appear cheap compared with current earnings or corporate assets. Folks often aim to own four funds: a large-company value fund, a large-company growth fund, a small-company value fund and a small-company growth fund.
But when it comes to the growth-value split, market weights aren't a whole lot of use. For instance, Standard & Poor's, a unit of McGraw-Hill, divides the S&P 500 into growth and value indexes.
It turns out that the companies in these two "style" indexes have a similar combined market value. But this is no great surprise: Standard & Poor's regularly rejiggers its indexes, to make sure half of the S&P 500's total value is in each index.
What to do? Rather than fussing around with all this, I would buy a total-stock-market index fund as your core U.S. stock holding. These total-market funds will give you the entire U.S. market -- large, small, growth and value -- in a single package, with everything in the right market weighting.
Total-market funds are sold by fund companies such as Fidelity Investments, T. Rowe Price Group, Charles Schwab Corp. and Vanguard. Having locked in broad U.S. stock-market exposure with a total-market fund, you can then add smaller stakes in other funds if you want to overweight particular sectors.
Heading Home
Thanks to their spectacular performance over the past five years, real-estate investment trusts are one of the market's most talked-about investments. Yet equity REITs account for only 2% of the total U.S. stock market.
So should you keep REITs at just 2% of your U.S. stock portfolio? That's certainly tempting, given today's rich REIT valuations. But on a long-term basis, I would be comfortable allocating 5% or even 10% of a stock portfolio to REITs.
Partly, that's because REITs are a great diversifier, often performing well when other U.S. stocks are suffering. In addition, while REITs themselves are small potatoes, they provide a great way to get real-estate exposure -- and real estate is a massive market. According to Federal Reserve data, all commercial and residential U.S. real estate is worth some $28 trillion, dwarfing the $13 trillion total value for all U.S. stocks.
Going Abroad
Like REITs, foreign stocks are also a good diversifier for a U.S. stock portfolio. But in the case of foreign stocks, I would be inclined to go for less than a market weighting.
Currently, foreign stocks -- including emerging markets -- account for roughly half of world stock-market value, with the other half represented by U.S. stocks. But I would limit foreign stocks to between 15% and 30% of your total stock portfolio.
Fact is, that 15% to 30% should be enough to get foreign stocks' diversification benefit. Moreover, when you tap your nest egg for income in retirement, you are likely to spend most of the money on U.S. goods and services. With that in mind, it seems sensible to keep the bulk of your portfolio in investments that are denominated in U.S. dollars.
Increasing Interest
According to New York's Bond Market Association , the value of all U.S. bonds comes to some $23 trillion, easily surpassing U.S. stocks, with their $13 trillion total value. I wouldn't pay any attention to these relative market weights, however, when settling on your stock-bond mix.
Instead, as with foreign stocks and REITs, I would focus chiefly on risk. But in the case of bonds, think about risk in two ways: How much risk can you afford to take -- and how much can you stomach?
Even if you have nerves of steel, you should stash money you will need in the next five years in a short-term-bond fund or a money-market fund. The reason: You don't want to find yourself short of money because you got hit with a stock-market collapse just before tapping your portfolio.
Meanwhile, even if you are decades away from your financial goals, you may decide to keep a hefty portion of your portfolio in bonds, because you find stock investing so nerve-racking. And that's a smart thing to do.
True, if you weighted stocks more heavily, you would likely clock higher long-run returns. But you will never collect those high returns if you panic and sell when stocks next plunge. Which brings me to probably the most important rule of portfolio building: In the end, the only sensible portfolio is the one you can live with. 如何规划你的投资组合
这是个有“份量”的话题。
你将如何安排大型股、小型股、外国股票、债券和其它投资在你的投资组合中的比例呢？
不论我何时面对这一问题，我的第一本能就是去参考投资者的集体意见－－你可以从每一类投资占市场总市值的比例上面了解到这方面的信息。
毕竟，这些市场权重可以告诉我们：投资者作为一个整体如何选择分配他们的资金。
但是，十有八九，你的投资组合最终可能与这些权重截然不同。你正在试图建立一个合适的投资组合吗？以下将告诉你市场权重在何时有用以及没用。
股票
假设你正盘算著如何将大型股共同基金和小型股共同基金按一定比例组建你的美国股票投资组合。我认为，这个时候市值权重最为有用。
据 Vanguard Group 称，当前标准普尔 500 股指中的大型蓝筹股占到美国股市总市值的大约四分之三，另外四分之一由中小型股构成。
这并不意味著你必须按照这一比例组建你的投资组合。相反，你也许会决定增加小型股的头寸。但即使如此，考虑市值权重仍然是有必要的，因为你可以藉此估计你的投资风险。
许多投资者喜欢对他们的美国股票投资组合作更深入细致的划分－－将资金在成长型和价值型基金之间分配。成长型基金购买销售额和利润迅速增长的股票，而价值型基金偏爱与当前收益或公司资产相比价格较为低廉的股票。人们通常希望拥有四种基金：大型股价值型基金、大型股成长型基金、小型股价值型基金和小型股成长型基金。
但是在确定成长型基金和价值型基金的比例时，市值权重就不是那么有用了。比如，标准普尔将标普 500 指数分割为成长指数和价值指数。
这两类指数的公司总市值相若。但这并不奇怪：标准普尔定期对指数进行调整，以确保两指数总市值各占标准 500 指数总市值的一半。
那么该如何操作呢？我不会仅仅把注意力放在这里，我会购买一个反映整个股市的指数基金作为核心的美国股票头寸。这些整体市场基金囊括了整个美国市场－－包括大型股、小型股、成长型和价值型股票，而且各类股票权重正合适。
整体市场基金在富达投资 (Fidelity Investments) 、 T. Rowe Price Group 、嘉信理财 (Charles Schwab Corp.) 以及 Vanguard 等基金公司有售。购买整体市场基金后你将与美国股市共沉浮，然后如果你想增加某一类股票的头寸，你可以略微增加一些对其它基金的投资。
房产
房地产投资信托基金 (REIT) 因在过去 5 年取得瞩目的表现，现在它是市场上的最热门投资之一。但是 REIT 市值仅相当于美国股市总市值的 2% 。
那么你持有的 REIT 是否也应当占美国股票投资组合的 2% 呢？鉴于当前 REIT 的价值很高，这个提议自然不错。但是从长期来看，我认为应该将 REIT 在投资组合中的比例提高至 5% ，甚至是 10% 。
部分原因在于 REIT 是出色的多样化工具，当其它美国股票下跌时它通常会表现很出色。此外，尽管 REIT 自身并非举足轻重，但它们是你参与房地产业的一个绝佳途径－－而房地产是一个庞大的市场。根据联邦储备委员会 (Federal Reserve) 的数据，美国所有的商业和民用地产价值在 28 万亿美元左右，令美国 13 万亿美元总市值的股票市场相形见绌。
海外
与 REIT 一样，外国股票对一个美国股票投资组合而言是一个很好的多样化工具。但是我倾向把外国股票的比例控制在市场权重以下。
当前，外国股票－－包括新兴市场－－占全球股票市场总市值的大约一半，美国股市占据了另外一半。但是我将会把外国股市头寸限制在整个股票投资组合的 15%-30% 之间。
事实是， 15% 至 30% 应该足以让你享受外国股票所带来的多样化好处。而且，当你退休提取你的储蓄投资时，你可能会将大部分钱花在美国商品和服务上面。考虑到这一点，将你的大多数投资组合维持在美元投资上面看起来是明智的。
胃口
据纽约债券市场联合会 (Bond Market Association) 称，美国债券的全部市值在 23 万亿美元左右，这一数字远远超过了美国股市的 13 万亿美元。但是在设立股票－债券组合时，我不会去考虑这些相对的市值权重。
相反，由于有了外国股票和 REIT ，我会著重关注风险。但是债券的风险要从两方面考虑：你能承受的风险多高；你的胃口有多大？
即使你勇气可嘉，你也应该将你在今后 5 年需要的钱投到短期债券基金或货币市场基金上面。原因是：你不想因股市崩溃而让自己陷入财务困境。
与此同时，如果你可以有几十年的时间去实现自己的财务目标，你也许会决定将你投资组合中很大一部分保留为债券，因为你发现股票投资太令人心惊肉跳。这是一个明智的举动。
是的，如果你加大股票投资，你可能会获得更高的长期回报。但是如果当股市下次暴跌时你感到恐慌并进行抛售，这些高收益将永远不会落入你的口袋。我由此想到了也许是最重要的一个建立投资组合的规则：能够让你坚持持有的投资组合才是你唯一明智的选择。
