Margin of safety = (Intrinsic value − Price) ÷ Intrinsic valueA margin of safety comes from facts you check with your own eyes — not from the absence of scary news.
Margin of Safety
The gap between what you pay and what you estimate something is worth — a deliberate cushion against your own mistakes, not just the market's.
What is margin of safety?
Margin of safety is the discount of the market price below your estimate of a business's intrinsic value — the cushion that protects you when your analysis is wrong. Benjamin Graham called it the central concept of investment: because every valuation contains errors, you buy at a price low enough that being moderately wrong still leaves an acceptable outcome.
- It is the percentage gap between price paid and estimated intrinsic value.
- Its purpose is to survive your own valuation errors, not just market swings.
- A large discount to an unreliable estimate is worth less than a small one to a careful estimate.
Definition
Margin of safety is the percentage discount of the market price below your estimate of intrinsic value. If you estimate a business is worth $100 per share and buy at $60, your margin of safety is 40%.
Benjamin Graham called it the central concept of investment. Its purpose is humility made quantitative: because your valuation will be wrong to some degree, you demand a price low enough that being moderately wrong still leaves an acceptable outcome.
Why it matters
Every valuation contains errors — optimistic growth, underestimated risks, unknowable surprises. A margin of safety converts those inevitable errors from catastrophic to survivable. It is risk management done at the moment of purchase, when you have the most control.
Simple example
A bridge engineer who expects 10-ton trucks builds for 30 tons. Not because she expects 30-ton trucks, but because steel weakens, loads are misjudged, and surprises happen. Buying at 60 cents on your estimated dollar applies the same engineering to investing.
Common misconception
"A bigger margin of safety always means a safer investment." Not if the intrinsic value estimate itself is unreliable. A 50% discount to a fantasy number is worth less than a 20% discount to a careful one. The margin is only as good as the estimate behind it.
- 1It is the percentage gap between price paid and estimated intrinsic value.
- 2Its purpose is to survive your own valuation errors, not just market swings.
- 3A large discount to an unreliable estimate is worth less than a small one to a careful estimate.
| Shortcut | The gap between what you pay and what you estimate something is worth — a deliberate cushion against your own mistakes, not just the market's. |
|---|---|
| Disciplined workflow | It is the percentage gap between price paid and estimated intrinsic value. → Its purpose is to survive your own valuation errors, not just market swings. → A large discount to an unreliable estimate is worth less than a small one to a careful estimate. |
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True story · The salad-oil crisis
Margin of safety is something you verify yourself
In late 1963 the Allied Crude Vegetable Oil scandal exploded: storage tanks pledged as collateral turned out to hold mostly seawater topped with a thin layer of salad oil. American Express, which had guaranteed the warehouse receipts, faced an enormous liability, and its stock was nearly cut in half. The headlines screamed bankruptcy.
Buffett did not read more headlines — he went out to restaurants and banks in Omaha and watched. People were still paying with American Express cards; travelers cheques were still being accepted everywhere. The franchise was intact. He put roughly 40% of his partnership into the stock, and within five years it had risen about five-fold.
A margin of safety comes from facts you check with your own eyes — not from the absence of scary news.
≈50%price collapse in the panic
≈40%of the partnership invested
≈5×within five years
True story · GEICO, 1976
Buying a great franchise on its worst day
By 1976 GEICO had under-priced policies and under-reserved for losses; the insurer was sliding toward insolvency and the stock had collapsed from $61 to about $2. Most investors saw a corpse. Buffett saw that the core advantage — selling insurance direct, at the lowest cost in the industry — was completely intact; the wound was bad management, and management can be replaced.
Berkshire invested roughly $45 million between 1976 and 1980 while a new CEO repaired pricing and reserves. The company recovered, compounded for two decades, and in 1995 Buffett paid $2.3 billion to buy the half of GEICO that Berkshire did not already own.
Ask first whether the problem kills the moat or just the quarter. A fixable wound at a panic price is where safety and return meet.
$61→$2the collapse
≈$45Minvested 1976–80
1995bought the whole company
True story · John Templeton, 1939
Buying everything under a dollar as the world went to war
In 1939, as war broke out in Europe and pessimism was total, young John Templeton borrowed $10,000 and placed one order: 100 shares of every NYSE and AMEX stock trading below $1 — 104 companies, 34 of them already in bankruptcy proceedings. He picked nothing; he priced despair across an entire basket.
He held for about four years and roughly quadrupled the money. Only four of the 104 positions went to zero. The systematic rule — maximum pessimism, wide diversification, a fixed holding period — did the work that stock-picking brilliance could not.
At the point of maximum pessimism, breadth and a written rule beat selectivity and nerve.
$10Kborrowed to invest
104stocks in the basket
≈4×in four years
Related tools
Frequently asked questions
What margin of safety should I demand?
There is no universal number. Graham suggested larger margins for uncertain businesses, smaller for stable ones. Many practitioners use 25–50% depending on predictability.
Does a high margin of safety guarantee a profit?
No. It improves the odds and limits damage from errors, but a business can deteriorate beyond any cushion. It is protection, not certainty.
Make margin-of-safety thinking part of every valuation:
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