Value investing: price, value and the margin of safety
Value investing rests on one idea: a share has an intrinsic value based on the business behind it, and the market price sometimes strays far from it. Buy well below value and you are paid for patience.
Graham’s foundations
Benjamin Graham, who taught Warren Buffett, set out the approach in Security Analysis (1934) and The Intelligent Investor (1949). Two of his ideas still anchor the field:
- Mr Market: imagine a business partner who offers each day to buy your share or sell you his, at prices driven by mood. You don’t have to trade with him. You can use his swings when they suit you.
- Margin of safety: only buy when price is well below your estimate of value, so that errors in your analysis, or bad luck, don’t ruin the investment.
Buffett’s evolution
Graham bought statistically cheap companies, sometimes trading below the cash on their books. Buffett, influenced by Charlie Munger, shifted towards quality: “a wonderful company at a fair price” over a fair company at a wonderful price. The focus moved to durable competitive advantages (moats), high returns on capital and good management, held for a long time.
How value is estimated
Approaches range from simple to detailed: comparing multiples with peers and history, valuing assets, or building a discounted cash flow (DCF) model of future free cash flow. All of them need judgement, and the output is a range, not a number.
Does it still work?
The “value factor” (buying statistically cheap stocks) underperformed growth for much of the 2010s, as low interest rates rewarded long-duration growth companies. It has had strong periods since. The broader principle (pay less than something is worth) remains sound, but cheap on a screen and undervalued are not the same thing.
Key takeaway
Value investing isn’t buying low P/E stocks. It is estimating what a business is worth, demanding a discount to that, and having the patience to wait.
Educational content only, not financial advice. Investing involves risk and you can lose money.