Economics
Discounted Cash Flow (DCF)
Quick fact
The DCF method was popularized by John Burr Williams in his 1938 book 'The Theory of Investment Value', where he argued that the value of a stock is the present value of all future dividends.
Why this is interesting
What is a dollar tomorrow worth today? Discounted cash flow answers that question, turning future promises into a number you can compare right now.
Read the full explanation
Understanding Discounted Cash Flow (DCF)
Think of DCF as a way to bring future money into today's terms. A dollar you receive a year from now is worth less than a dollar today because you could invest today's dollar and earn interest. DCF reverses that: you take the expected future cash flows (like profits or dividends) and apply a discount rate—reflecting the risk and opportunity cost of capital—to shrink each future amount to its present value. Summing all those present values gives you the total estimated worth of the investment. For example, if you expect $100 next year and use a 10% discount rate, the present value is about $90.91.
A deeper explanation
DCF works because money has time value: a dollar today can be put to work to generate more dollars in the future. The discount rate captures both the risk-free rate (compensation for waiting) and a risk premium (compensation for uncertainty). The formula for a single cash flow is PV = CF / (1+r)^n. For multiple periods, you sum the discounted values, often including a terminal value to capture cash flows beyond a forecast horizon. This method is fundamental for capital budgeting decisions—companies use DCF to evaluate whether a project will create value. Its main vulnerability is sensitivity to assumptions: small changes in the discount rate or terminal value can swing the valuation dramatically, which is why analysts perform sensitivity analysis. Despite limitations, DCF remains the gold standard for intrinsic valuation because it focuses on cash generation rather than accounting earnings or market sentiment.