INVESTOR LETTER #39
What Is the Price-to-Earnings (P/E) Ratio? Formula & Importance
Learn what the Price-to-Earnings (P/E) Ratio is, how it is calculated, and why investors use it to evaluate stock valuation, compare companies, and determine whether a stock may be undervalued or overvalued.
INVESTOR NOTE
A business owner thinks in decades. A speculator thinks in minutes.
Buying a Business, Not Just a Stock
Imagine a local coffee shop earns ₹10 lakh every year. The owner offers to sell you the entire business for ₹1 crore. Before saying yes, you'd naturally ask, 'If this business earns ₹10 lakh every year, why should I pay ₹1 crore?' This is exactly the question the P/E Ratio helps answer in the stock market. It tells you how much you're paying compared to what the business currently earns.
What the Market Is Willing to Pay
Every company has earnings, and every company has a market price. The P/E Ratio simply compares these two numbers. If investors believe a business has an excellent future, they are often willing to pay much more for each rupee of current earnings. If they expect little growth, they usually pay much less.
Thinking Like a Shop Buyer
Suppose two grocery stores each earn ₹20 lakh every year. One is located in a busy neighborhood with growing demand, while the other is in an area where customers are slowly disappearing. Even though today's profits are the same, most buyers would happily pay more for the first store because they expect higher future earnings. The stock market thinks the same way.
Why a High P/E Doesn't Always Mean Expensive
Many beginners assume that a stock with a high P/E is overpriced. But sometimes investors are paying a premium because they expect the company to grow rapidly for many years. A wonderful business can look expensive today but still turn out to be a great investment if its earnings continue growing.
Why a Low P/E Isn't Always a Bargain
Imagine someone is selling a restaurant for a surprisingly low price. At first, it sounds like a great deal. But after visiting, you discover customers have stopped coming, the equipment is outdated, and the building needs major repairs. The low price wasn't a bargain—it reflected real problems. A low P/E can sometimes tell a similar story.
The Market Always Looks Ahead
The stock market doesn't pay for yesterday's earnings alone. It constantly tries to estimate what the business will earn in the future. That's why two companies with similar profits can trade at completely different P/E Ratios. Expectations often matter more than current numbers.
Growth Changes Everything
Imagine two students score the same marks today. One studies harder every year and keeps improving, while the other has stopped putting in effort. If you had to predict who would perform better five years from now, your choice would be obvious. Businesses are judged the same way. Faster expected growth usually leads to a higher P/E Ratio.
Quality Deserves a Premium
People willingly pay more for a house in a safe neighborhood than an identical house in a risky area. Similarly, investors often pay higher valuations for companies with trusted brands, loyal customers, strong management, and durable competitive advantages because they believe these businesses are more reliable.
Comparing Apples with Apples
Comparing the P/E Ratio of a bank with a software company or a steel manufacturer rarely makes sense. Every industry grows at a different pace and faces different risks. The P/E Ratio is most useful when comparing companies operating in the same industry.
One Year Can Fool You
Sometimes profits jump because of a one-time event like selling land or receiving a tax benefit. Sometimes profits fall because the company made a temporary investment for future growth. Looking at only one year's earnings can make the P/E Ratio appear unusually high or unusually low.
When Earnings Disappear
If a company earns very little profit, its P/E Ratio can become extremely high. If the company reports a loss, the P/E Ratio usually becomes meaningless because there are no positive earnings to compare with the share price.
The Cheapest Stock Isn't Always the Best
Imagine choosing between two cars. One costs half as much but constantly breaks down, while the other costs more but runs smoothly for years. Paying less doesn't always save money. The same principle applies to stocks. A low P/E without a strong business can become an expensive mistake.
The Best Businesses Rarely Look Cheap
Many legendary companies have spent years trading at seemingly expensive valuations because investors recognized their exceptional quality. Businesses that consistently grow earnings, generate strong cash flow, and build competitive advantages often deserve higher valuations than average companies.
Valuation Is Only One Piece of Investing
Buying a wonderful business at a reasonable price is usually better than buying a weak business simply because it looks cheap. The P/E Ratio helps you think about valuation, but it says nothing about management quality, competitive advantage, debt, or future growth.
How Value Investors Think
Value investors don't search for the lowest P/E stocks. They search for businesses whose future earnings and quality are better than what the current price suggests. Sometimes that company has a low P/E. Sometimes it doesn't. The goal is to find value, not just a small number.
Mistakes Beginners Often Make
Many beginners buy stocks simply because the P/E Ratio is low or avoid stocks because the P/E Ratio is high. They ignore why the market has assigned that valuation. Understanding the business always comes before judging the valuation.
Questions Every Investor Should Ask
Before looking at the P/E Ratio, ask yourself: Is the company consistently growing its earnings? Does it have a durable competitive advantage? Is management trustworthy? Are profits backed by healthy cash flow? Only after understanding the business should you decide whether the current valuation offers a reasonable opportunity.
INVESTOR PRINCIPLE