Once a stock passes the Two-Minute Story Test, Lynch still needed one more number before he pulled the trigger. That number is PEGY — and it tells you whether you’re paying a fair price for what you’re actually getting.
Passing the Two-Minute Story Test tells you a company is worth investigating. But it doesn’t tell you whether the stock is worth buying at today’s price.
A great business at the wrong price is a bad investment.
Lynch needed a single, practical number to answer the price question for growth stocks. Not an elaborate model. Not a fifteen-tab spreadsheet. A ratio simple enough to calculate with a pencil and a few minutes of research — but powerful enough to compare any two growth stock candidates head to head.
He called it the PEGY ratio.
Start Here: The P/E Problem
To understand PEGY, start with a simpler ratio you’ve probably heard of: the P/E ratio, or price-to-earnings ratio. It tells you how much investors are paying for each dollar a company earns.
If a stock trades at $60 per share and the company earns $3 per share, the P/E is 20. Investors are paying $20 for every $1 of annual earnings.
A high P/E means investors expect strong growth — they’re paying a premium today for earnings they expect tomorrow. A low P/E means expectations are modest.
The problem: P/E says nothing about how fast the company is actually growing. A P/E of 20 looks expensive if earnings are growing at 4% per year. But it looks quite reasonable if earnings are growing at 25% per year. Same number, completely different meaning.
Lynch’s solution was to divide the P/E by growth — to see whether investors are paying a fair price for what the company is delivering.
But he added one more thing. He included the dividend yield — the annual dividend payment as a percentage of the stock price — alongside the growth rate. His reasoning: dividends are real cash returned to shareholders every year. They contribute to your total return just as surely as price appreciation does. Ignoring them would make income-producing companies look more expensive than they actually are.
Put it all together and you get PEGY:
PEGY = P/E ÷ (EPS growth rate % + dividend yield %)
EPS stands for earnings per share — the company’s total profit divided by the number of shares outstanding. It’s each shareholder’s proportional slice of the company’s earnings. If a company earns $10 million and has 5 million shares outstanding, EPS is $2.00.
Reading the Number
A PEGY of 1.0 means you’re paying a price that is perfectly in line with the company’s expected growth and income. The market has priced in exactly what the company appears to offer.
A PEGY below 1.0 suggests the stock may be undervalued relative to its growth and income. You may be getting more growth than you’re paying for.
A PEGY above 1.0 suggests the market may be pricing in more growth than the company will deliver. You’re paying a premium — which may or may not be justified.
Lynch used PEGY as a comparison tool, not a hard buy trigger. He wasn’t looking for a mechanical rule that said “buy everything below 1.0.” He was looking for a way to rank candidates that had already passed his story test and category analysis. Given two fast growers that both tell a compelling story, which one gives you more growth and income for each dollar of price? PEGY answers that directly.
A Worked Example
Let’s put numbers to it. You’re looking at two fast-growing companies — Company A and Company B — and trying to decide which is the better buy.
Company A:
– Stock price: $60 / EPS: $3.00 → P/E = 20
– Expected EPS growth rate: 18% / Dividend yield: 0%
– PEGY = 20 ÷ (18 + 0) = 1.11
Company B:
– Stock price: $48 / EPS: $2.00 → P/E = 24
– Expected EPS growth rate: 20% / Dividend yield: 2%
– PEGY = 24 ÷ (20 + 2) = 1.09
Both PEGYs are above 1.0 — neither is screaming cheap. But Company B’s PEGY is slightly lower. You’re getting slightly more growth-and-income for each dollar of price. If the stories are equally compelling and the risks are comparable, Company B is the better entry.
Now add a third candidate:
Company C:
– Stock price: $40 / EPS: $2.00 → P/E = 20
– Expected EPS growth rate: 22% / Dividend yield: 1%
– PEGY = 20 ÷ (22 + 1) = 0.87
Company C’s PEGY is below 1.0. For every dollar of price, you’re getting more growth-plus-income than the market is currently pricing. That’s the kind of candidate Lynch got excited about — not because the ratio alone made the decision, but because it suggested the market might be underappreciating what this company is delivering.
Where Does the Growth Rate Come From?
Lynch typically used the company’s expected long-term earnings growth rate — ideally a five-year consensus estimate. You can find these on financial data sites that compile analyst projections.
He wasn’t chasing precision. He knew that five-year earnings forecasts are imperfect. He was looking for reasonable estimates that allowed reasonable comparisons. A company growing earnings at roughly 15% and a company growing at roughly 25% are meaningfully different — even if both estimates are off by a percentage point or two.
What he avoided: using last year’s earnings growth as the expectation for the next five years. One great year is not a forecast. He wanted to understand whether the company’s growth runway — the territory it still has to expand into — could sustain that pace going forward. A restaurant chain with 50 locations in one city has more runway than one with 3,000 locations in every market. The future earnings growth story has to be grounded in something real.
PEGY Beyond Lynch
Here is something important that this series wants you to carry into everything else you read on this blog.
PEGY is not a Peter Lynch tool. It is not limited to his framework or his style of investing. It is a universal comparison tool — one that puts price, growth, and income on equal footing regardless of the investing approach.
In Growth Investing — the screening process covered in the Growth Investing series on this blog identifies companies that pass five financial gates: revenue growth, earnings growth, manageable debt, no recent losses, and a trailing P/E at or below the S&P 500 historical average. When two companies both pass all five gates, how do you choose between them? PEGY. The lower the PEGY, the more growth you’re getting per dollar of price. It’s the tiebreaker when scorecards are close.
In Value Investing — the core discipline covered in the Intrinsic Value series is to buy stocks trading below their calculated intrinsic value — meaning below what the business is actually worth. But sometimes a stock looks cheap because it is cheap in the wrong way: earnings are stagnant, the industry is declining, and the discount reflects a permanent problem, not a temporary one. PEGY helps flag this. A “cheap” stock with a PEGY of 4.0 or 5.0 isn’t cheap relative to its growth — it’s just cheap. A P/E of 10 on a company growing earnings at 2% per year is not a bargain. It’s a slow-motion problem.
The concept at the core of PEGY — that price means nothing without context for what the company is actually delivering — applies everywhere. It keeps you from falling in love with a low P/E without asking why it’s low. And it keeps you from being scared off by a high P/E without asking whether fast growth justifies it.
Lynch didn’t invent the idea that price and growth belong together. He made it practical enough to calculate in five minutes, with numbers anyone can find for free.
Where PEGY Fits in Lynch’s Process
Lynch’s process has a clear sequence:
- Find the idea — from daily life, from your work, from observation
- Categorize the stock — slow grower, stalwart, fast grower, cyclical, turnaround, or asset play
- Pass the Two-Minute Story Test — why do I own this, what has to happen, what could go wrong?
- Run the PEGY check — is the price reasonable given the growth and income I’m getting?
PEGY is the last gate before the deeper research begins. If a stock makes it through all four steps, Lynch was ready to dig into the financial statements, visit the company if possible, and build real conviction before committing capital.
The ratio doesn’t replace judgment. But it keeps you from two common and costly mistakes: buying a great story at a terrible price, and passing on a good story because the P/E looked high when the growth rate justified every bit of it.
A Note to Luca and Lili
PEGY is one of those tools that rewards clarity.
To calculate it, you need three things: the P/E ratio (price divided by earnings per share), the expected earnings growth rate (which requires you to have a genuine view on the company’s future), and the dividend yield (which is available on any financial data page in seconds). The arithmetic takes thirty seconds.
What takes longer is forming a genuine view on the growth rate. That’s where the real work lives. A fast grower’s future growth depends on runway. A stalwart’s consistency depends on whether the competitive advantages that drove past growth are still intact. A slow grower’s dividend sustainability depends on cash flow holding up.
The ratio is simple. The inputs require thought. That combination — simple math built on real understanding — is the signature of every practical tool in investing. Anyone can calculate PEGY once they have the numbers. The skill is having numbers worth calculating with.
Learn PEGY. Use it every time you’re comparing two candidates. And remember that the goal isn’t to find the lowest number — it’s to find the best balance of price, growth, and income for the risk you’re taking.
— Papa
The One-Sentence Summary
PEGY — calculated as the P/E ratio divided by the sum of the expected earnings growth rate and the dividend yield — is Peter Lynch’s tool for comparing growth stock candidates on equal footing, where a PEGY below 1.0 suggests the market may be underpricing the company’s growth, a PEGY above 1.0 suggests the opposite, and the ratio applies equally well to growth, value, and any other style of investing.
The Lynch Investing series continues. Explore all Lynch Investing posts on the Lynch Investing series page.
— Jim