Stock Valuations and the “Rule of 20” (2024)

The beginning of a new decade is one of those personal milestones that often prompts reflection and introspection. Where am I in life’s journey? How do I feel about the decade that just ended? What lies ahead?

Investors are no different and may have posed the same questions about the financial markets at the end of last year. Their review of the past decade was quite likely positive and upbeat. Stocks and bonds both had a remarkable run in this period. The S&P 500 index soared by an annualized 13.6% in the 2010s and the Barclays Aggregate Bond index1rose by 3.7% on an annual basis.

U.S. investors in particular were perhaps also gratified to see the dominant performance of their domestic stock market relative to the rest of the world. U.S. stocks generated cumulative returns of over 200% in the last ten years and outpaced stocks in both the developed and emerging foreign markets by over 150% in aggregate2.

As the stock market gets off to a strong start this year, concerns about valuations are now starting to grow. During a year of virtually no earnings growth, how could stocks perform so well? As Price-to-Earnings (P/E) multiples rise, are stocks expensive now or even overvalued?

The symmetry and numerology of the year 2020 brings to mind the good old“Rule of 20”as a useful way to think about these questions. A tried and tested heuristic in the stock market has been derived from the combined levels of the P/E ratio and the rate of inflation. Over the years, markets have shown a distinct tendency to revert back to a sum of 20 for these two metrics.

In other words, the Rule of 20 suggests that markets may be fairly valued when the sum of the P/E ratio and the inflation rate equals 20.

P/E + Inflation = 20

The stock market is deemed to be undervalued when the sum is below 20 and overvalued when the sum is above 20.

This seemingly simplified insight has nonetheless been surprisingly effective. Here are some historical observations3for the Rule of 20.

  • Markets rarely trade at equilibrium, so it’s no surprise that the Rule of 20 is also rarely achieved in precision.
  • The combined P/E ratio and inflation rate have ranged from a low of 14 to a high of 34.
  • Over the last 50 years or so, the average P/E is just below 16, average inflation is 4% and the average sum of P/E and inflation, as expected, is close to 20.

Let’s compare recent valuation and inflation trends against this historical backdrop.

Valuations in the last 5 years have trended higher. The average P/E in this period is measured at 18.1, which is admittedly higher than the 50-year average of 15.8.

However, the upward drift in P/E ratios is rooted in the fundamental drivers of low inflation and low interest rates, and not in speculation or euphoria as some might fear. Inflation in this period has come in significantly below its 50-year average at just 2.0%. Muted levels of inflation have been one of the most remarkable outcomes of this lengthy economic cycle.

As a result, the sum of P/E and inflation in the last 5 years registers at 20.1 which is almost surgically aligned with the Rule of 20. It also provides us with a key insight and takeaway. Higher-than-normal P/E ratios in recent years are being supported by lower-than-average inflation, and consequently, lower-than-average interest rates.

The P/E ratio, both forward and trailing, and inflation rate so far in 2020 are a notch higher than the 5-year average shown above. The average P/E this year is close to 19, inflation is around 2.5% and the sum of P/E + Inflation is just above 21.0.

  1. These levels are only slightly higher than the Rule of 20 norm and still close to fair valuations.
  2. We also attribute this small uptick in the P/E ratio to expectations of higher normalized growth in the second half of 2020, triggered by the recent truce in the trade war and concerted global central bank easing.

Any discussion of valuations or growth at this point would be incomplete without reference to the current concerns about the coronavirus. In this regard, we observe that geopolitical or “geomedical” events rarely have a lasting impact on the markets even though they inflict significant human pain and suffering. At this point, we hold a similar view that the current fears of a pandemic will also pass without meaningful permanent economic damage. We, therefore, believe that our valuation views discussed above in the context of the Rule of 20 still remain intact.

We believe that the U.S. stock market is fairly valued at these prices. We also believe that a U.S. recession is unlikely in the near future based upon the health of the consumer and the job market. We nevertheless remain vigilant to changing sources of risk and guard against them through a focus on high quality investments.

1Bloomberg Barclays US Aggregate Bond index
2Based on the S&P 500, MSCI EAFE and MSCI EM indexes
3Source: Evercore ISI
42020 data is through February

Stock Valuations and the “Rule of 20” (2024)

FAQs

What is the rule of 20 in stock market? ›

Rule of 20: Stocks are considered fairly valued when the sum of the S&P 500 forward P/E ratio and the year-over-year change in the consumer price index (CPI) is equal to 20 (or inexpensive when it's below 20).

What is the rule of 20 in market valuation? ›

In other words, the Rule of 20 suggests that markets may be fairly valued when the sum of the P/E ratio and the inflation rate equals 20. The stock market is deemed to be undervalued when the sum is below 20 and overvalued when the sum is above 20.

What is 20 percent stock rule? ›

An overview of the so-called New York Stock Exchange (NYSE) 20% rule requiring stockholder approval before a listed company can issue 20% or more of its outstanding common stock or voting power.

How do you solve stock valuation? ›

The most common way to value a stock is to compute the company's price-to-earnings (P/E) ratio. The P/E ratio equals the company's stock price divided by its most recently reported earnings per share (EPS). A low P/E ratio implies that an investor buying the stock is receiving an attractive amount of value.

What is the rule of 20 Peter Lynch? ›

Higher discount rates naturally equate to lower equity valuations. One simplistic measure of this is Peter Lynch's Rule of 20. This suggests that stocks are attractively priced when the sum of inflation and market P/E ratios fall below 20. Today CPI is running at 6.4% year over year, and P/Es for the S&P 500 are 18.3x.

What is the rule of 20 Bloomberg? ›

A measure of stock valuations called the Rule of 20 states that the stock market is fairly valued when the sum of the average price-earnings ratio and the rate of inflation is equal to 20. Above that level, stocks begin to get expensive; below it, they're bargains.

What is the valuation rule? ›

This valuation rule will apply to exclusive Principal-Agent related cases. Most of these valuation rules are case specific, the all powerful GST council has also listed up certain businesses such as the sale of foreign currency and life insurance business etc and their specific valuation rules (Under clause 6 above).

What is the fair valuation rule? ›

The rule will provide that determining fair value in good faith requires the oversight and evaluation of pricing services. Boards or valuation designees of funds that use pricing services will be required to establish a process for approving, monitoring, and evaluating each pricing service provider.

What is the 80 20 20 rule investing? ›

In investing, the 80-20 rule generally holds that 20% of the holdings in a portfolio are responsible for 80% of the portfolio's growth. On the flip side, 20% of a portfolio's holdings could be responsible for 80% of its losses.

What is the 7% rule in stocks? ›

The 7% stop loss applies to any stock purchase at any level. If you bought a stock at 45 and the buy point was at 43, you want to calculate the 7% sell rule from your purchase price.

What is rule 21 in stock market? ›

Before this chart causes you a severe migraine, let me explain what you're looking at in simple terms. The relationship can be referred to as the “Rule of 21,” which says that the sum of the P/E ratio and CPI inflation should equal 21.

What is the easiest way to calculate the value of a stock? ›

Price-to-earnings ratio (P/E): Calculated by dividing the current price of a stock by its EPS, the P/E ratio is a commonly quoted measure of stock value. In a nutshell, P/E tells you how much investors are paying for a dollar of a company's earnings.

What is the formula for valuation? ›

The formula for valuation using the market capitalization method is as below: Valuation = Share Price * Total Number of Shares. Typically, the market price of listed security factors the financial health, future earnings potential, and external factors' effect on the share price.

Which is the most ideal method of valuation of stock? ›

The P/E method is perhaps the most commonly used valuation method in the stock brokerage industry. By using comparison firms, a target price/earnings (or P/E) ratio is selected for the company, and then the future earnings of the company are estimated.

What is the 15 15 15 rule in stock market? ›

Meaning of the 15-15-15 rule in Mutual Funds

The Investment: You should invest Rs 15,000 per month. The Tenure: The total of your investment should be 15 years. It means that you will invest Rs 15,000 every month for the next 15 years. The Return: Your expected returns on your investment should be 15%

What is rule 21 in the stock market? ›

Before this chart causes you a severe migraine, let me explain what you're looking at in simple terms. The relationship can be referred to as the “Rule of 21,” which says that the sum of the P/E ratio and CPI inflation should equal 21.

What is the rule of 70 in the stock market? ›

The rule of 70 is used to determine the number of years it takes for a variable to double by dividing the number 70 by the variable's growth rate. The rule of 70 is generally used to determine how long it would take for an investment to double given the annual rate of return.

Can you make money investing $20 in stocks? ›

Even if you only have $20, that's a great start to get your feet wet in the world of investing. Today, even a little bit of money can get you access into the stock market or real estate investments.

Top Articles
Latest Posts
Article information

Author: Lilliana Bartoletti

Last Updated:

Views: 6140

Rating: 4.2 / 5 (73 voted)

Reviews: 80% of readers found this page helpful

Author information

Name: Lilliana Bartoletti

Birthday: 1999-11-18

Address: 58866 Tricia Spurs, North Melvinberg, HI 91346-3774

Phone: +50616620367928

Job: Real-Estate Liaison

Hobby: Graffiti, Astronomy, Handball, Magic, Origami, Fashion, Foreign language learning

Introduction: My name is Lilliana Bartoletti, I am a adventurous, pleasant, shiny, beautiful, handsome, zealous, tasty person who loves writing and wants to share my knowledge and understanding with you.