The Core Philosophy
Warren Buffett's investment philosophy can be distilled into one sentence from his 1989 shareholder letter: "It's far better to buy a wonderful company at a fair price than a fair company at a wonderful price."
This was a departure from his mentor Benjamin Graham, who focused on buying mediocre companies at very cheap prices ("cigar butt" investing). Charlie Munger convinced Buffett that the compounding power of a great business at a reasonable price would outperform a mediocre business at a bargain price over long holding periods.
The shift was from statistical cheapness to business quality. Buffett stopped looking for the cheapest stocks in the market and started looking for the best businesses that happened to be available at fair prices.
Owner Earnings: Buffett's DCF
In his 1986 shareholder letter, Buffett introduced the concept of "owner earnings":
Owner Earnings = Net Income + Depreciation/Amortization - Maintenance Capital Expenditures
This is what the owner of the business would actually receive in cash each year after keeping the business running at its current competitive level. It differs from reported free cash flow because it distinguishes between maintenance capex (required to sustain the business) and growth capex (optional spending to expand).
Buffett then estimates intrinsic value as the present value of all future owner earnings. He has said this is the only theoretically correct way to value a business — and it's essentially a DCF model, just described in plainer language.
The key insight: a company that can grow owner earnings at 15% per year is worth far more than its current earnings suggest. Buffett pays up for growth — but only when the growth is protected by a competitive moat.
Circle of Competence
Buffett insists on investing only in businesses he can understand. He calls this the "circle of competence" — the set of industries and business models where you have enough knowledge to assess competitive dynamics, future cash flows, and management quality.
Buffett famously avoided technology stocks for decades because he couldn't predict which companies would win. He invested in Coca-Cola, Gillette, and American Express instead — businesses with straightforward economics he could project 10-20 years forward with confidence.
The practical implication: the accuracy of your valuation depends on how well you understand the business. A perfectly constructed DCF model is worthless if the growth rate assumption is wrong because you misjudged the competitive dynamics.
Knowing what you don't know — and staying out of those areas — is as important as understanding what you do know.
Moat First, Price Second
Buffett evaluates businesses in a specific order:
- Does the business have a durable competitive advantage (moat)?
- Is management honest and capable?
- Is the price reasonable relative to owner earnings?
The moat comes first because it determines the reliability of future cash flows. A business without a moat will see its returns competed away, making any valuation projection unreliable.
Buffett's four favorite types of moats (from his letters and talks):
- Toll bridge businesses — Companies that collect a fee on every transaction and face little competition. Visa, Mastercard, and railroad companies exemplify this.
- Consumer monopolies — Brands so strong that consumers specifically request them. Coca-Cola, See's Candies, and Gillette.
- Switching cost businesses — Products so embedded in customer operations that switching is painful. Enterprise software, industrial equipment.
- Low-cost operators — Companies with structural cost advantages that competitors can't match. GEICO, Costco.
When Buffett Actually Buys
Buffett has described his approach as "waiting for the fat pitch" — a baseball metaphor meaning he only swings at obvious opportunities. He might look at hundreds of businesses and buy one or two per year.
The conditions that typically trigger a Buffett purchase:
- A wonderful business temporarily out of favor (American Express during the salad oil scandal, Goldman Sachs during 2008)
- A fair price for a business with predictable, growing owner earnings
- Management he trusts to allocate capital wisely
- A margin of safety large enough that the investment works even if his assumptions are somewhat wrong
What Buffett does NOT do: he doesn't try to time the market, he doesn't buy based on macro forecasts, and he doesn't trade frequently. His preferred holding period is "forever."
Applying Buffett's Framework Today
You can apply Buffett's principles using the tools on FairValueLabs:
- Identify the moat — Check the Moat Ratings for stocks with 4-5 star competitive advantages
- Verify financial health — Use the Risk Audit to ensure the Z-Score is safely above 1.8
- Estimate fair value — Our DCF model calculates intrinsic value from owner earnings (free cash flow)
- Demand margin of safety — Look for positive margin of safety on the individual ticker pages
- Use the Strike Zone — The Strike Zone automates Buffett's triple filter: quality + safety + value
The key difference between Buffett's approach and purely quantitative investing: Buffett adds qualitative judgment about management quality and business trajectory that no formula can capture. Our quantitative tools get you 80% of the way — the last 20% requires your own research and judgment.