Margin of safety is the gap between what a business is worth and what you're paying for it — the single idea Graham considered the cornerstone of intelligent investing.
Margin of Safety = (Intrinsic Value - Price) / Intrinsic Value
Why it matters more than being "right." No valuation model is precise — assumptions about growth, discount rates, and margins are always somewhat uncertain, and reality will diverge from any single forecast. A large margin of safety is your buffer against being wrong: if your estimate of intrinsic value is off by 20%, a large enough discount to that estimate still protects you from a bad outcome, while a stock priced right at your estimate leaves no room for error.
How Intrinsic uses it. It's the third number in the verdict panel, always shown alongside price and blended IV. A positive margin of safety means the stock is priced below the estimate; a negative one (shown in red) means it's priced above it — the verdict badge (Fat Pitch / Fair Value / Overpriced / Speculative) is really just a set of named ranges of this one number.
A margin of safety is not a guarantee. It's a discipline for sizing how wrong you can afford to be, not a promise that the price will ever reflect the estimate at all.