Where it sits
A moat is not an advantage. It is the reason an advantage persists.
Tell it apart
What it doesn't mean
Buffett's 1995 example is an insurer's ROCK-BOTTOM OPERATING COSTS, and he describes management having WIDENED the moat by further reducing underwriting and loss adjustment expenses. The moat was the cost structure, not the product.
It is formalised into five named types — network effect, intangible assets such as brands and patents, cost advantage, switching costs, and efficient scale — and used operationally in equity research, including formal 'wide-moat' ratings.
What it really means
The half of the metaphor that always gets dropped is the half that matters.
Buffett's actual sentence, from the 1995 shareholder letter: In business, I look for economic castles protected by unbreachable moats.
Castles and moats. Two things. A moat around nothing is a wet ditch. It is not a strategy, and a company that has spent years building defensibility around a business nobody wants has built exactly that.
The second correction is about what a moat actually is, and the 1995 example is not what people expect. He was discussing an insurer, and the moat was its rock-bottom operating costs — with management having widened it by further reducing underwriting and loss adjustment expenses.
Not the product. Not the brand. The cost structure. A company that can profitably charge a price at which competitors lose money has a moat that no amount of competitor enthusiasm can cross.
The concept has since been formalised into five named types, and knowing all five is what stops the word being a synonym for good:
Network effect — the product is more valuable because others use it. Intangible assets — brands, patents, licences. Cost advantage — you can profitably undercut. Switching costs — leaving is expensive, disruptive or frightening. Efficient scale — the market is only big enough for the incumbents already in it.
Only the first requires users. Contemporary business writing talks almost exclusively about network effects, which is one-fifth of the framework and the hardest to construct deliberately.
And the underlying test is simpler than the taxonomy. A moat is not an advantage. It is the reason an advantage survives contact with competitors who have noticed it. Anyone can be profitable before anybody is looking.
This page explains the terms and is not investment advice.
Where it comes from
the medieval defensive water ditch around a castle
Buffett pairs it with the castle — the moat is worthless without something worth defending. The half of the metaphor that gets dropped is the half that contains the business.
- 1986–2016
The term recurs across three decades of Berkshire Hathaway shareholder letters — used more than twenty times.
- 1995
Buffett writes: in business, I look for economic castles protected by unbreachable moats — discussing an insurer's cost advantage.
In real life
- Buffett's 1995 example was an insurer whose rock-bottom operating costs virtually no competitor could match — the moat was the cost structure, not the product.
- Switching costs: a firm whose accounts, payroll and records all live in one software system finds moving so disruptive that it stays, even when a cheaper rival appears.
- Efficient scale: a town only big enough for one cement works — a second plant would split the market and leave both struggling, so nobody builds one.
Questions
Q01What did Buffett actually write?
In the 1995 letter: 'In business, I look for economic castles protected by unbreachable moats.' The castle is in the sentence too, and it is the half that gets dropped.
Q02What are the five moat types?
Network effect, intangible assets (brands, patents, licences), cost advantage, switching costs, and efficient scale.
Q03Who else uses the term?
Equity research firms apply it operationally, including formal 'wide-moat' designations. This page explains the terms and is not investment advice.