Wide, narrow & shallow moats
“Wide moat” and “narrow moat” are common shorthand among value investors for how durable a company’s competitive advantage looks: a wide moat should hold competitors off for decades, a narrow one for years, and a shallow one is an edge that exists but shouldn’t be leaned on. Used loosely, the labels are a judgment call — two analysts can look at the same company and disagree.
On this site the labels mean something narrower and more checkable, and that’s a deliberate difference from common usage: our tiers are exact bands of the Moat Score, not a committee’s opinion. Wide is 80–100, Narrow is 60–79, Shallow is 40–59, and below 40 is no moat. A company scoring 79.5 is Narrow and one scoring 80.0 is Wide — the boundary is sharp because the score is. Treat tiers as a reading aid over the number, not a separate verdict.
How the Moat Index measures this
The tier follows mechanically from the composite score described in the methodology — nothing else feeds it. You can read the top of the ranking on the Index, filter by tier in the screener, or start from the wide-moat preset screens.