Discounted Cash Flow (DCF)
Discounted cash flow (DCF) values a business as the sum of all the cash it will hand its owners, translated into today’s dollars. Money arriving in year ten is worth less than money arriving tomorrow, so each future cash flow gets shrunk by a discount rate reflecting risk and the cost of waiting.
The math
Take a company expected to produce $100M of owner cash flow next year, growing 2 percent forever. At a 10 percent discount rate, its value is $100M divided by the 8-point spread between the two rates: $1.25B.
Now nudge the discount rate down to 8 percent and the value jumps to $1.67B. One assumption moved two points and roughly $417M of estimated value appeared from nowhere.
| Base case | Optimistic case | |
|---|---|---|
| Discount rate | 10% | 8% |
| Rate minus growth | 8 points | 6 points |
| Estimated value | $1.25B | $1.67B |
An investor who pays $1.6B because the optimistic version felt right has staked $350M of real money on a single soft input.
The trap
False precision. A DCF prints one number to the dollar, yet the terminal value, the piece guessed with the least confidence, often carries 60 to 80 percent of the total.
And an analyst who starts from the current stock price can always find a growth rate that justifies it, which quietly turns the model from a valuation tool into a rationalization engine.
The move
Run it in reverse. Take the current price, solve for the growth the market is implying, then judge whether that growth is plausible for this business.
Work in ranges rather than point estimates, and buy only when the conservative scenario still leaves room. Cross-check the output against earnings yield and owner earnings: a DCF that disagrees with every simpler measure is usually the estimate that is wrong, not the market.