“A quick way to tell if a stock is overpriced is to compare the price line to the earnings line. If you bought familiar growth companies – such as Shoney’s, The Limited, or Marriott – when the stock price fell well below the earnings line, and sold them when the stock price rose dramatically above it, the chances are you’d do pretty well.” Peter Lynch

As the former head of Fidelity’s flagship Magellan Fund, Peter Lynch produced an annualized rate of return of 29.2% over his 13-year stint at the helm. This track record has arguably placed him as the best mutual fund manager of all time.

In his best-selling book, “One Up On Wall Street,” Lynch revealed a powerful charting tool, called the “Peter Lynch chart,” that greatly simplified his investment decisions. This simple graph plots the stock price against its “earnings line,” a theoretical price equal to 15 times the earnings per share.

When a stock trades well below its earnings line, you should buy, according to Lynch’s theory. When it rises above its earnings line, you should sell. For example, the Wal-Mart Stores (ticker: WMT ) share-price line fell below the Lynch line at about $55 in March 2010. It didn’t climb back over the Lynch line until June 2012, when shares were $67.50. Had you bought the first crossover and sold the second, you would have gained $12.50 a share, or about 23%.

The idea behind this technique is simple. Lynch believe that mature, stable companies are worth roughly 15 times their annual earnings. And over the last 135 years, this has proven to be the mean valuation of the S&P 500 index.

This is known as a the P/E ratio. It is merely the price of the stock divided by its earnings per share. The resulting multiple represents how many times you are paying for last year’s earnings at today’s stock price.

All things being equal, the lower the number the better. Low P/E ratios mean that you are getting more earnings for your investment dollar. And since most large cap stocks eventually trade for at least 15 times earnings, you are more likely to see your shares appreciate as they return to the 15 P/E level.

This simple idea was the basis of Lynch’s investment approach and the reason he created the chart whichconsists of only two lines. The first is the stock price. The second is the hypothetical stock price if it were to trade at a P/E of 15 (the earnings line).

It is a well-known fact among experienced investors that a stock’s price follows its earnings. Over multi-year periods, stock prices move in sync with changing company earnings.

But over the short term, stock prices are unpredictable. This is what creates valuable opportunities for savvy and patience investors.

Furthermore, a good rule of thumb is that the P/E ratio of any fairly valued company will equal its earnings growth rate. A company with a P/E ratio that is half its growth rate is very positive. A company with a P/E ratio that is twice its growth rate is deemed negative.

Thirteen attributes you should investigate for in a stock with the potential for 10x growth, according to Peter Lynch:

1. The company name is dull or ridiculous.
2. The company does something dull and boring
3. The company does something disagreeable or disgusting.
4. The company is a spin-off like the Baby Bells.
5. Institutions don’t own it and analysts don’t follow it.
6. There are negative rumors about it, like Waste Management.
7. There is something depressing about it such as SRB, which provides burial services.
8. That it is a company in a no growth industry, since it’s in a non competitive business.
9. It has a niche such as drug companies.
10. People have to keep buying the products such as drugs, food and cigarettes.
11. The company is the user of technology such as Domino’s.
12. The company insiders are buyers of the stock.
13. The company is buying back its shares.

Best stocks to avoid is the hottest stock in the hottest industry. Negative growth industries do not attract competitors. Additionally, avoid companies with excessive debt on its balance sheet and invest in companies that have little or no debt.

The debt must always be lower than the equity. If the company has a debt lower than 50% of the equity, it is considered to be in a good financial position. If it is lower than 25%, it’s excellent. When the debt is above 75% of the equity, it is recommended to avoid that company.

References:

1. https://finance.yahoo.com/news/peter-lynch-earned-29-13-231636799.html
2. https://tofinancialfreedom.co/en/one-up-on-wall-street-summary-book/
3. https://www.forbes.com/sites/investor/2021/04/16/lynchs-one-up-on-wall-street-inspired-screening-strategy/