The world’s greatest investor has a checklist. It’s stricter than you might think — and every item on it has a reason.
Everyone’s heard of Warren Buffett. He’s the most famous investor in the world. His company, Berkshire Hathaway, has compounded shareholder money at roughly 20% per year for six decades. He lives in the same house he bought in Omaha, Nebraska in 1958, eats a McDonald’s breakfast every morning, and has donated the overwhelming majority of his fortune to charity.
But most people who’ve heard of him don’t actually know what he does. They know he’s rich. They know he invests in stocks. And they’ve heard phrases like “buy what you know” or “be greedy when others are fearful” — but not the methodology behind them.
This post is about the methodology. Specifically: what Buffett actually looks for when he evaluates a company. Because understanding his checklist — even if you never use it yourself — will change how you think about businesses forever.
“A Wonderful Company at a Fair Price”
Here is the sentence that defines Buffett’s entire approach:
“A wonderful company at a fair price is far better than a fair company at a wonderful price.”
When people think about value investing — the discipline of buying stocks that are underpriced — they often think: find cheap stocks. Buy something the market doesn’t like, wait for the price to recover, sell it.
Buffett started his career doing something like that, following the teachings of his mentor Benjamin Graham. But over time, he came to believe that buying mediocre businesses at big discounts is a harder, slower way to make money than buying great businesses at reasonable prices and holding them for decades.
The key word is wonderful. What does Buffett mean by wonderful? That’s what the rest of this post is about.
His filter has three stages: the business first, management second, valuation third. A company that fails the first test never gets to the second.
The First Test: The Moat
Buffett calls the most important quality in a business its economic moat — the defensible advantage that lets it keep competitors away and maintain high profits for decades, not just a few years.
The metaphor is literal. A medieval castle with a wide moat full of water was hard to attack. A business with a wide economic moat is hard to compete against. Rivals try to take your customers, undercut your prices, or build a better product — but if your moat is real, they can’t close the gap.
Buffett identifies five types of moat:
Brand. Some companies can charge more for their product simply because of the name on the label. Coca-Cola doesn’t taste dramatically different from a generic cola — but people pay a premium for the real thing because of what the brand represents. That premium, multiplied across billions of transactions, is enormous.
Low-cost producer. If your structural cost to make or deliver a product is lower than any competitor’s, you can price below them, survive price wars, and still make money. GEICO, the car insurance company Buffett owns, built its moat this way — by cutting out agents and selling direct, it could offer lower premiums than competitors and still profit.
Switching costs. Some products are painful to leave. If a company’s software is deeply embedded in a hospital’s operations, switching to a competitor means retraining every doctor and nurse and risking patient data. That friction — the switching cost, or how difficult and expensive it is for a customer to leave — is a moat. Oracle, the enterprise software company, is one of the strongest examples: its database and business-management systems are woven into a company’s financial reporting, payroll, and supply chain. Migrating off Oracle means re-architecting those workflows from scratch, retraining entire departments, and accepting serious risk of data loss or error during the transition. Most companies look at that cost and decide it’s not worth it — and Oracle’s moat stays intact.
Network effects. Some products get more valuable as more people use them. A credit card network with 100 million cardholders is far more useful to a merchant than one with 100,000. The larger the network, the more merchants accept it; the more merchants accept it, the more cardholders want it. That self-reinforcing dynamic is one of the most powerful moats that exists.
Toll bridge or regulatory franchise. Some businesses are the only path through. BNSF Railway runs tracks through parts of the American West that no one else can replicate — if you want to ship goods by rail through those corridors, you use BNSF. There is no substitute. Regulated utilities work similarly: they’re granted exclusive service territories in exchange for regulatory oversight, which means their moat is built into the law.
Buffett says the moat is the single most important criterion. Everything else is secondary. A great balance sheet in a business without a moat is a temporary advantage. A genuine moat lasts decades.
The Second Test: Simplicity and Operating History
Buffett only buys what he can fully understand. He calls this staying within his circle of competence — the set of businesses and industries where he can make accurate judgments. If he cannot explain how a company makes its money in plain English, he does not own it. This is famously why he avoided technology stocks for decades: he couldn’t predict which platforms and products would dominate, so he stayed away.
He also requires a track record. Specifically: 10 or more years of consistently profitable operation. He is deeply skeptical of turnarounds — companies trying to fix something that’s broken — and he doesn’t invest in unproven business models. “Turnarounds seldom turn,” he has said more than once.
He also wants to believe the business will still be dominant 20 years from now. He asks: what will this industry look like in two decades, and will this company still be leading it? That question rules out a lot.
The Management Filter
Assuming a company passes the business quality tests, Buffett looks at the people running it.
He wants managers he would be comfortable leaving the business to for 20 years without checking in.
What does that mean, practically? Five things.
Rationality in capital allocation. The CEO’s most important job is deciding what to do with the cash the business generates. Does management invest in high-return opportunities, or squander it on ego acquisitions and empire-building?
Candor with shareholders. Buffett reads annual reports obsessively. He respects executives who discuss their failures honestly — not just their successes. Managers who explain away every bad result with external factors are a red flag.
Resistance to institutional imperative. Most executives do what other executives do: copy competitors, chase trends, make acquisitions because everyone else is making acquisitions. Buffett wants the rare CEO who thinks independently, even when it’s uncomfortable.
Owner-operator mindset. Managers who think like owners — who have significant personal stakes and take the long view — make better decisions than hired hands optimizing for this year’s bonus.
No empire building. Buffett is deeply suspicious of CEOs who grow headcount for its own sake, make large acquisitions into unrelated businesses, or expand scope to boost their own prestige or compensation.
The Numbers: What Has to Be True
After business quality and management, Buffett looks at the financials. He is not primarily a numbers-first investor — he leads with qualitative judgment — but the numbers have to confirm the picture.
Return on Equity (ROE) — how much profit the company generates relative to what shareholders have invested. The formula: net income divided by shareholders’ equity. Buffett wants this to be consistently 15% or higher, sustained over a decade, and achieved without excessive debt. (Debt can artificially inflate ROE by reducing the equity denominator — a warning sign, not a strength.)
Owner Earnings — Buffett’s preferred measure of what a business truly earns for its owners. Standard accounting profits (what companies are required to report) can overstate or understate economic reality. Owner earnings gets closer to the truth:
Owner Earnings = Net Income
+ Depreciation & Amortization
− Maintenance Capital Expenditures
± Changes in Working CapitalTo unpack this in plain English: a company’s reported profit includes a subtraction for depreciation — the accounting cost of assets wearing out over time. But the actual cash cost of keeping the business competitive (buying new equipment, maintaining infrastructure) might be different from what accounting rules suggest. Owner earnings replaces the accounting depreciation number with the actual cash the business has to spend to stay in the game. What’s left over — what flows to owners without them having to give any back — is the real return on owning the business.
Return on Invested Capital (ROIC) above the cost of capital. ROIC measures how much profit the business earns on all the capital it has deployed — both equity and debt. Buffett wants this to be consistently above what the business costs to finance — a hurdle sometimes called the cost of capital, or the minimum return required to justify holding the investment. A business earning 20% on its invested capital when capital costs 9% is compounding owner wealth every year, without needing anything from you. That’s the wealth-creation machine.
Low long-term debt. Buffett is deeply conservative on leverage — the use of borrowed money to finance operations or growth. He prefers businesses that could retire all their debt within two to three years of earnings if they needed to. High debt amplifies both gains and losses; for the businesses Buffett owns, the moat already provides the compounding — debt adds risk without adding value.
Predictable earnings. Buffett wants to be able to forecast a company’s earnings ten years out with high confidence. Erratic, cyclical, or lumpy earnings make that impossible — and if you can’t project the earnings, you can’t estimate what the business is worth. This is why he has avoided most commodity businesses and cyclicals throughout his career.
Valuation: Intrinsic Value and Margin of Safety
Once Buffett has identified a business that passes all his quality tests, he asks: what is it worth, and what is the market currently charging?
His definition of intrinsic value:
The present value of all owner earnings the business will generate over its remaining life, discounted at the long-term Treasury rate.
You’ve seen the concept of present value before — the idea that a dollar received in the future is worth less than a dollar today, because money invested today can grow. Buffett projects out the owner earnings he expects the business to generate and converts them to a present-day number using the long-term Treasury rate (the interest rate the U.S. government pays on long-term bonds — a proxy for the risk-free return available in the market).
Notice what he doesn’t use: the complex discount rate calculations that adjust for the riskiness of the specific company. His logic: a business with a genuine, wide moat already has the risk discount embedded in the predictability of its cash flows. He doesn’t need to add an extra risk premium on top. The certainty itself is the safety.
The other piece is margin of safety — a principle he inherited from his mentor Benjamin Graham and made his own. Even after a careful valuation, Buffett buys at a significant discount to intrinsic value — typically 25 to 50% below his estimate. This cushion protects him if his analysis turns out to be slightly wrong. “It’s far better to be approximately right than precisely wrong.”
One final test he applies: the one-dollar test. For every dollar of earnings management has retained and reinvested (rather than paying out as dividends), has the company created at least one dollar of market value over time? If retained earnings flow into the business but the stock price doesn’t reflect that accumulation, something is wrong — value is being destroyed, not created.
What He Won’t Touch
Understanding what Buffett avoids is as instructive as understanding what he buys.
He won’t buy businesses he doesn’t understand — full stop. He won’t buy airlines, steel companies, or commodity producers because they have no pricing power and require enormous, continuous capital investment with returns that rarely exceed what capital costs. He avoids turnarounds, hot IPOs with no track record, and companies loaded with debt. He’s skeptical of businesses that need constant reinvestment just to stay in place. And he avoids any management team that has been dishonest with shareholders — that’s disqualifying, regardless of the financials.
He also avoids what he calls diworseification — spreading capital across so many investments that the strong ones can no longer drive meaningful results. Berkshire’s top five holdings routinely represent over 70% of its equity portfolio. Concentration, in his view, is a feature of careful analysis — not a risk.
A Note to Luca and Lili
I’ve spent a long time studying Warren Buffett — not just reading about him, but reading what he actually wrote. The annual letters to Berkshire Hathaway shareholders, going back to 1977, are freely available online. They are among the clearest, most honest pieces of business writing you will ever read. He doesn’t use jargon to seem smart. He uses plain language because he actually is.
Here is the thing I want you to carry from this post.
Buffett’s criteria aren’t just a checklist for stock picking. They’re a way of thinking about any business — including one you might run, or work for, or start. What does this business do that a competitor can’t easily copy? Does management care about the people who’ve trusted them with capital? Does the business create real value, or does it just move numbers around?
You can apply those questions long before you own a single stock. In fact, applying them to the world around you is how you start to see it clearly.
— Papa
The One-Sentence Summary
Warren Buffett evaluates every company through three sequential filters — the business first (does it have a wide, durable competitive moat?), management second (does leadership think like owners and act with candor?), and valuation third (is the market offering a meaningful discount to intrinsic value?) — and walks away if anything fails.
Next: Warren Buffett’s Advice, Part 2 — Buffett is famous for picking individual stocks with extraordinary care. But when ordinary investors ask him what they should do, his answer is different — and it might surprise you.
— Jim