A Stock is Not an Index! 【投资个股 和 投资指数是完全不同】

A Stock is Not an Index!【投资个股 和 投资指数是完全不同】轻松聊投资 CLEC投资理财教育学院 博文日期: May 02, 2022

Posted April 26, 2022 by Nick Maggiulli

Last week Netflix's share price fell 37% after reporting its first loss in subscribers in more than a decade:

发表于 2022 年 4 月 26 日，作者 Nick Maggiulli

上周，Netflix 的股价在十多年来首次出现用户流失后下跌了 37%：

As Michael Batnick tweeted, this erased all of Netflix's gains going back to February 2018:

Michael Batnick @michaelbatnick

Netflix just wiped out all of its gains going back to February 2018.

正如迈克尔巴特尼克在推特上所说，这抹去了 Netflix 自 2018 年 2 月以来的所有收益：

迈克尔·巴特尼克@michaelbatnick

Netflix 刚刚抹去了自 2018 年 2 月以来的所有收益。

With the stock nearly 40% off its highs, a few readers have asked me: is now the right time to buy?

Rather than discuss the merits and risks of Netflix in particular, I thought it would be more useful to turn this into a broader discussion of understanding why buying an individual stock while it's down bad isn't the same as buying an index that's down bad.

随着股价从高点下跌近 40%，一些读者问我：现在是买入的合适时机吗？

与其特别讨论 Netflix 的优点和风险，我认为将其转变为更广泛的讨论会更有用，以了解为什么在股价下跌时购买单个股票与购买下跌时下跌的指数不同。

As I've written about previously, when it comes to buying an asset or basket of assets following a large decline, you only need two pieces of information to determine whether you should buy: (1) the percentage gain needed to reach a new all-time high, and (2) an estimate for how long it will take to reach those new highs.

正如我之前所写的那样，在大幅下跌后购买资产或一揽子资产时，您只需要两条信息即可确定是否应该购买：（1）达到新的全部所需的百分比收益 -时间高点，以及（2）估计需要多长时间才能达到这些新高点。

In Netflix's case, the stocks is down about 39% today. Therefore, to reach new all-time highs, it will need to increase by roughly 64% [Note: 1/(1-0.39) - 1 = 1/.61-1~ 0.64]. So, if you think Netflix will take 1 year to reach these new highs, buying today means expecting a 64% return over the next year. If you think Netflix will take two years to reach new highs, buying today would get you a 28% annualized return. And so forth.

就 Netflix 而言，该股今天下跌了约 39%。因此，要达到历史新高，它需要增加大约 64% [注：1/(1-0.39) - 1 = 1/.61-1~ 0.64]。因此，如果您认为 Netflix 将需要 1 年时间才能达到这些新高，那么今天购买意味着预计明年将获得 64% 的回报。如果您认为 Netflix 需要两年时间才能达到新高，那么今天购买将为您带来 28% 的年化回报率。等等。

But here is where things break down between buying an individual company that has declined a lot and buying an index that has declined a lot-there is no guarantee that the individual company will ever recover. Netflix may never get back to its old highs. It may slowly decline into the graveyard of market history.

但是，在买入大幅下跌的个别公司和买入大幅下跌的指数之间，情况就出现了问题——不能保证个别公司会永远复苏。Netflix 可能永远不会回到过去的高点。它可能会慢慢沦为市场历史的坟墓。

However, with an index fund like the S&P 500 this is unlikely to occur.

Though there are exceptions to this rule (i.e. Japan since 1989, Greece since 2008, etc.), the probability of the S&P 500 never recovering from a crash is quite low.

然而，对于像标准普尔 500 指数这样的指数基金来说，这种情况不太可能发生。

尽管这条规则也有例外（即自 1989 年以来的日本，自 2008 年以来的希腊等），但标准普尔 500 指数永远不会从崩盘中恢复的可能性非常低。

Why?Because, unlike an individual company, the S&P 500 is always changing. To demonstrate this, consider Morgan Housel's tweet showing the growth of $1 invested in U.S. stocks since 1871 (from the

Shiller data):

为什么？因为，与单个公司不同，标准普尔 500 指数总是在变化。为了证明这一点，请考虑 Morgan Housel 的推文，该推文显示自 1871 年以来投资于美国股票的 1 美元增长（来自

席勒数据）：

Looking at this you might think that you could have invested $1 in 1871 and just waited to get rich. Unfortunately, it's not that simple. The companies that represented U.S. stocks in 1871 are very different from the companies that represented U.S. stocks in 1971 and in 2021. Though the line has gone up and to the right, what that line represents has changed dramatically over the decades.

看到这里，您可能会认为您本可以在 1871 年投资 1 美元，然后就等着致富。不幸的是，事情并没有那么简单。1871 年代表美股的公司与 1971 年和 2021 年代表美股的公司有很大的不同。虽然这条线向上和向右移动，但这条线所代表的内容在过去几十年中发生了巨大变化。

How so?With economic and technological development over time, new companies have been brought into the index and old companies have been kicked out. As Geoffrey West stated in Scale:

The Universal Laws of Life, Growth, and Death in Organisms, Cities, and Companies:

怎么会这样？随着经济和技术的发展，新公司被纳入指数，老公司被淘汰。正如 Geoffrey West 在 Scale 中所说：

有机体、城市和公司的生命、成长和死亡的普遍规律：

Of the 28,853 companies that traded on U.S. markets since 1950, 22,469 (78 percent) had died by 2009. Of these 45 percent were acquired by or merged with other companies, while only about 9 percent went bankrupt or were liquidated; 3 percent privatized, 0.5 percent underwent leveraged buyouts, 0.5 percent went through reverse acquisitions, and the remainder disappeared for "other reasons."

自 1950 年以来在美国市场交易的 28,853 家公司中，到 2009 年有 22,469 家（78%）死亡。其中 45% 被其他公司收购或合并，而只有约 9% 破产或被清算； 3% 私有化，0.5% 进行了杠杆收购，0.5% 进行了反向收购，其余的因“其他原因”消失了。

West's research shows that public companies in the U.S. are in a constant state of flux. Based on his analysis, roughly half of all public U.S. companies in existence today won't be in existence a decade from now. They will either merge, be acquired, go bankrupt, or find some other way out of the market.

Because of this, what we call "the market" changes from year to year.

韦斯特的研究表明，美国的上市公司处于不断变化的状态。根据他的分析，在今天存在的所有美国上市公司中，大约有一半在十年后将不复存在。他们要幺合并，要幺被收购，要幺破产，要幺另谋出路。

正因为如此，我们所说的“市场”每年都在变化。

More importantly, this rate of change might actually be accelerating. As the chart below (from this Innosight study)

illustrates, the average longevity of a company in the S&P 500 index has been on a gradual decline over the past few decades:

更重要的是，这种变化速度实际上可能正在加速。如下图（来自 Innosight 研究）

说明，标准普尔 500 指数公司的平均寿命在过去几十年中一直在逐渐下降：

In 1965 the average company tenure in the S&P 500 was 33 years, but today it's closer to 20 years. While this metric isn't a perfect measure of creative destruction among U.S. stocks, it suggests that companies in the S&P 500 are being replaced at a faster rate than in the past.

1965 年，标准普尔 500 指数公司的平均任期为 33 年，但如今已接近 20 年。虽然这一指标并不是衡量美国股票创造性破坏的完美指标，但它表明标准普尔 500 指数中的公司正在以比过去更快的速度被取代。

Regardless of how quickly companies are moving in and out of the index, you can see that owning an index is fundamentally different than owning a basket of individual stocks. While your basket of individual stocks will remain the same over time, the index will not.

无论公司进出指数的速度有多快，您都可以看到拥有指数与拥有一篮子个股有着根本的不同。虽然您的一篮子个股会随着时间的推移保持不变，但指数不会。

For example, if you own an S&P 500 index fund, your underlying holdings will change based on the work done by Standard and Poor's research teams. If they decide to add or remove a company from the index, you will automatically add or remove that company from your holdings as well. In this way, owning a passive index fund, such as the S&P 500, is like owning a momentum strategy where the biggest risers are added and the biggest laggards are dropped out of the index over time.

例如，如果您拥有标准普尔 500 指数基金，您的基础资产将根据标准普尔研究团队所做的工作而变化。如果他们决定从指数中添加或删除公司，您也将自动从您的持股中添加或删除该公司。通过这种方式，拥有一个被动指数基金，例如标准普尔 500 指数，就像拥有一个动量策略，随着时间的推移，最大的上涨者被加入，最大的落后者被剔除出指数。

But this isn't the only way in which a stock is different than an index.

The returns are far better in indices as well. As I stated in Chapter 18 of

Just Keep Buying:

但这并不是股票不同于指数的唯一方式。

指数的回报也好得多。正如我在第 18 章所述

继续购买：

If you look at the universe of individual stocks in the U.S. going back to 1963, the median one year return is 6.6%, including dividends. This means that if you grabbed an individual stock at random at any point in time since 1963, you would've earned roughly 6.6% over the next year. However, if you did the same thing with the S&P 500, you would've earned 9.9% instead.

如果你看一下美国 1963 年以来的个股，包括股息在内，一年的中位回报率为 6.6%。这意味着，如果您在 1963 年以来的任何时间点随机获取一只股票，那么您在接下来的一年中将获得大约 6.6% 的收益。然而，如果你对标准普尔 500 指数做同样的事情，你将获得 9.9% 的回报。

Of course, many of you reading this know a lot of this already. "A stock isn't an index?No sh*t Nick." Yes, / know you know this.

But what you may not realize is the benefits that this provides to index investors. Think about it. We get a list of which companies to own and in which percentages to own them and we don't have to pay for any of it. Other market participants do all the work for us. They spend their time, money, and energy setting prices and figuring out what we should invest in. And we don't have to lift a finger.

当然，很多阅读这篇文章的人已经知道很多了。“股票不是指数？不，尼克。” 是的，/知道你知道这一点。

但您可能没有意识到这为指数投资者带来的好处。想想看。我们得到一份清单，其中列出了拥有哪些公司以及拥有它们的百分比，我们不必为此支付任何费用。其他市场参与者为我们完成所有工作。他们花费时间、金钱和精力来设定价格，并弄清楚我们应该投资什么。而且我们不必动一根手指头。

Because of this, we can set our portfolios and do something more productive with our time. But what makes this situation even better is that we are likely to beat 70-80% of other active investors simply by buying and holding this list of companies!It's the biggest free lunch in investing and there is no close second.

So, if you want to buy the Netflix dip, be my guest. You may be rewarded handsomely for doing so.

But if you want to join the rest of us "passively" getting rich, you know what to do.

正因为如此，我们可以设置我们的投资组合并利用我们的时间做一些更有成效的事情。但是让这种情况变得更好的是，我们很可能仅仅通过购买和持有这份公司名单就击败了 70-80% 的其他活跃投资者！这是投资中最大的免费午餐，只有唯一没有第二。

所以，如果你想买大跌抄底 Netflix，请成为我的客人。你可能会因此而获得丰厚的回报。

但如果你想加入我们其他人的“被动”致富，你知道该怎么做。