What Is Margin of Safety?
The cushion between price and estimated worth.
The answer in plain English
Margin of safety is the gap between a stock's price and its estimated intrinsic value, expressed as a percentage.
Simple answer
Margin of safety is the gap between a stock's price and its estimated intrinsic value, expressed as a percentage.
Why this matters
A larger cushion limits downside if your estimates prove optimistic.
Good signs
A positive margin of safety means the stock trades below its estimate.
Warning signs
A negative margin means the stock trades above the estimate.
Easy mistake to make
Relying on it alone, or forgetting that the intrinsic value behind it is itself uncertain.
How Wall Street Score helps
Shown as a labeled metric and on the valuation thermometer on the stock page.
Where the Cushion Comes From
The margin of safety is the gap between a stock's current price and its estimated [intrinsic value](/education/intrinsic-value), expressed as a percentage. If a stock trades at $80 and the estimated intrinsic value is $100, the margin of safety is 20% — you are buying at a 20% discount to the estimate.
The concept originates with Benjamin Graham, the father of value investing, who argued that investors should demand a meaningful discount to intrinsic value before buying. The discount serves as a cushion: if your estimate is wrong (the true value is lower than you calculated), the discount limits your downside. If your estimate is right, the discount provides upside as the price converges to value.
How the Percentage Is Calculated
The formula is straightforward: Margin of Safety = (Intrinsic Value − Current Price) / Intrinsic Value × 100.
A positive margin of safety means the stock trades below the estimate. A negative margin means the stock trades above the estimate — the market is paying a premium, and there is no cushion.
WallStreetScore displays the margin of safety as a labeled metric on each stock page, alongside the intrinsic value estimate and the current price. The [Opportunity Score](/education/opportunity-score) incorporates this metric into a broader rating that combines price-to-value with other near-term signals.
It is important to understand that the margin of safety is only as reliable as the intrinsic value behind it. If the estimate is inflated by overly optimistic growth assumptions, the 'cushion' is illusory — you may be paying full price while thinking you are getting a discount.
When the Cushion Is Real Versus Illusory
A genuine margin of safety exists when the stock is trading below a conservative, well-grounded estimate of intrinsic value. This typically happens when the market has overreacted to bad news, when a sector is out of favor, or during broad market downturns that drag good companies down with bad ones.
An illusory margin of safety exists when the stock looks cheap but the intrinsic value estimate is too high. This is common with companies in secular decline — the backward-looking financials may still look decent, but the forward-looking estimate fails to account for deteriorating fundamentals. The stock is 'cheap' because the market has correctly anticipated that future earnings will be much lower.
To distinguish between the two, always ask: Why is the stock trading at a discount? Is the market overreacting to a temporary problem, or has something fundamentally changed about the business? If the answer is the latter, the margin of safety may not be real. For more on this trap, see [Common Stock Valuation Mistakes](/education/valuation-mistakes).
Practical Application
How large should the margin of safety be? There is no universal answer, but many value investors look for at least 20–30% — enough to absorb estimation errors and unexpected bad news without permanent capital loss. For higher-conviction investments with very stable businesses, a smaller cushion may be acceptable. For riskier or more uncertain situations, a larger cushion is warranted.
The margin of safety should never be used in isolation. A stock with a 40% margin of safety but a deteriorating business and eroding [moat](/education/moat-score) may still be a poor investment. A stock with no margin of safety but a wide moat and accelerating growth may be worth buying at a premium. The best investments combine a reasonable margin of safety with strong [business quality](/education/wallstreet-score) — which is exactly what the WallStreetScore and Opportunity Score are designed to help you assess together.
Apply this to a real stock
Use Wall Street Score to search a company and compare its score with revenue, earnings, cash, debt, valuation and risks.
Educational research only. Not investment advice.