Financial Concepts（3）: Diversification

从一个权威的网上摘下来的系列文章，请注意加粗的文字和有标记的地方。

Many individual investors can't tolerate the short-term fluctuations in the stock market.

许多个人投资者不能容忍股市中一些短期的波动。

Diversifying your portfolio is the best way to smooth out the ride.

分散风险是消除（部分）波动的的最好的办法（没有之一）。

Diversification is a risk-management technique that mixes a wide variety of investments within a portfolio in order to minimize the impact that any one security will have on the overall performance of the portfolio.

分散风险是一种风险控制的技术，它通过广泛投资，形成资产组合。这样，任意一种有价证券的价格起伏对整个资产组合的影响就可以降到最低。

Diversification lowers the risk of your portfolio.

风险分散可以降低投资组合的风险。

Academics have complex formulas to demonstrate how this works, but we can explain it clearly with an example:

学者们有相当复杂的公式来解释分散风险是如何工作的，但对于我们大众来说，这就不必了。

我们下面举一个简单的例子，就足以解释为什么分散风险可以起到“分散风险”的作用了。

Suppose that you live on an island where the entire economy consists of only two companies: one sells umbrellas while the other sells sunscreen.

假设你住在一个岛上，这个岛上只有一家卖伞的公司和一家卖墨镜的公司。

If you invest your entire portfolio in the company that sells umbrellas,you'll have strong performance during the rainy season, but poor performance when it's sunny outside.

如果你把全部资产都投向卖伞的公司，那么在雨季，你的收益将很高，但是在晴天，你就只有哭的份儿。

The reverse occurs with the sunscreen company, the alternative investment; your portfolio will be high performance when the sun is out, but it will tank when the clouds roll in.

反之，如果你把所有资产都投资于卖墨镜的公司，那么在天晴的季节，你可以获得丰厚的汇报，但是在雨天，谁会去买你的墨镜呢？

（为什么是你的墨镜，如果你去做股权投资，你就是股东，你就是公司的一份子了）

Chances are you'd rather have constant, steady returns.

可能你更想长期地拥有一份比较稳定的收入。（假定你此时并不知道当地的气候环境）

The solution is to invest 50% in one company and 50% in the other.

一个较好的解决方案就是，把你的资产同时投向这两家公司，一家一半。

Because you have diversified your portfolio,

正是因为你使得你的投资组合多元化，

you will get decent performance year round instead of having either excellent or terrible performance depending on the season.

一年下来你的投资收益可能还不错，而不是说“你的收益将取决于天气”。

这相当于把命运掌握在了自己的手中，不是靠天吃饭。

There are three main practices that can help you ensure the best diversification:

这里主要有3条可以帮助你最佳地分散风险的经验。

1.    Spread your portfolio among multiple investment vehicles such as cash,stocks,bonds,mutualfunds and perhaps even some real estate.

1. 让你的资产组合多元化。比如现金、股票、债券、基金甚至一些房地产。

2.    Vary the risk in your securities. You're not restricted to choosing only blue chip stocks. In fact, it would be wise to pick investments with varied risk levels; this will ensure that large losses are offset by other areas.

2. 投资不同风险档次的有价证券。你不一定非要选蓝筹股。实际上，可能成长型+价值型的风格会明智。这样可以确保某一方面的比较大的损失可以由别的方面的收益来弥补。

3.    Vary your securities by industry. This will minimize the impact of industry-specific risks.

3. 投向不同的行业。这样可以降低某些特定行业的风险。（比如，一些周期性行业。也比如，一些正在“去产能”的行业。）

 

Diversification is the most important component in helping you reach your long-range financial goals while minimizing your risk.

在实现长期投资目标的同时，把所需要承受的风险降到最低，风险分散将是最重要的一个部分。

At the same time, diversification is not an ironclad guarantee against loss. No matter how much diversification you employ,investing involves taking on some risk.

但值得注意的是，分散风险并不能完全确保毫无损失。无论你怎么分散你的风险，就投资本身而言，它也必定具有风险。

Another question that frequently baffles investors is how many stocks should be bought in order to reach optimal diversification.

另一个常常困扰投资者的问题是，为了实现最优的风险分撒，我该买多少股票呢？

According to portfolio theorists, adding about 20 securities to your portfolio reduces almost all of the individual security risk involved.

根据投资组合理论，大概20只股票就可以把你的资产组合中的个股风险降到很低了。

（这也是我在同花顺模拟的时候，总共就5万的模拟金额，持股却有20多只，个股风险不小的2个多月，

从2017年清明节“雄安新区”概念炒作之后，到2017年7月17日黑色星期一，我的模拟收益仍不止10%的原因。）

This assumes that you buy stocks of different sizes from various industries.

当然，这要假定你投资了很多不同的行业，且各个行业的股票仓位并不相等。

（因为D(aX+bY) = a^2 D(X)+ b^2 D(Y) + 2*a*b*Cov(X,Y)...）