Margin of Safety

The margin of safety is one of Benjamin Graham's most important concepts, later embraced by Warren Buffett. The idea is simple: no valuation model is perfect. Estimates of future cash flows can be wrong. Businesses face unexpected challenges. By only buying when a stock trades at a meaningful discount to your estimated intrinsic value — typically 20–50% — you build in protection against being wrong.

A 30% margin of safety means if you estimate a stock is worth $100, you only buy it at $70 or below. Even if your estimate is optimistic by 15%, you can still profit. Without a margin of safety, even a small error in your assumptions can result in a loss.

Example: Seth Klarman of Baupost Group, one of the world's most successful value investors, has consistently emphasized that buying with a large margin of safety is the most important risk control tool an investor has. His fund has averaged high single-digit to low double-digit returns over decades with very few down years.

BMInsider's 100X Insider Reports always include a margin of safety calculation alongside the fair value estimate — helping subscribers identify whether a stock is actionable at current prices.