The question behind the question
Asking whether to use a discounted cash flow or comparables is really asking which uncertainty you would rather carry. A DCF concentrates uncertainty in your forecast and your discount rate. Comparables concentrate it in the market's current mood and in your peer selection. Neither eliminates it, and any valuation presenting a single number as if it had is hiding the interesting part.
The serious answer is that stage determines weighting, not choice. Run both, state how you weighted them, and defend the weighting.
When a DCF earns its place
A DCF is the theoretically correct approach and the practically fragile one. It works when cash flows are genuinely forecastable: an established revenue base, understood unit economics, a capital structure that is not about to change, and a business model that will not be reinvented in the explicit forecast period.
Its strength is that it forces every assumption into the open. The discount rate has to be built rather than asserted. Capital expenditure has to be justified. Working capital has to move with volume. In a negotiation, that transparency is an asset: you are arguing about specific assumptions rather than about a multiple someone picked.
Its weakness is terminal value. For a growth company, 70% to 85% of DCF value routinely sits in the terminal year. At that point the analysis is mostly a statement about the world in year six, dressed in five years of arithmetic. That is acceptable when acknowledged and tested with a sensitivity grid. It is not acceptable when presented as precision.
When comparables carry the weight
Comparables answer the question a buyer is actually asking: what are companies like this one trading at right now. At earlier stages, where cash flows are speculative, that is the more honest framing. It is also how the market itself prices — investors work from multiples and sanity-check with a DCF far more often than the reverse.
The weakness is selection. Peer sets are chosen on business model, growth rate, margin profile and scale — not on sector label. A 40%-growth software company at 80% gross margin is not comparable to a 12%-growth software company at 55%, whatever the industry classification says. Every valuation memo should list the rejected candidates and the reason for rejection, because that list is what pre-empts the pushback.
The second weakness is timing. Multiples move with the cycle. A comparable set assembled at a market peak values your business at the peak, and the same set eighteen months later can produce half the number with no change to the business at all.
Weighting by stage
- Pre-revenue: comparables, scorecard and venture method carry it. A DCF here is theatre; run it only as a sanity check on implied exit expectations.
- Early revenue, under roughly US$5m: comparables lead, weighted perhaps 70/30, with a DCF testing whether the implied multiple requires heroic growth.
- Scaling, US$5m to US$50m: genuinely balanced. Both methods are informative and disagreement between them is itself a finding worth investigating.
- Mature or cash-generative: the DCF leads, with comparables confirming that the market agrees with your discount rate.
- Real estate and infrastructure: discounted cash flow dominates, because the cash flows are contractual and the terminal value is an observable cap rate rather than a guess.
The third method nobody runs properly
Precedent transactions — what acquirers actually paid for similar businesses — is the most neglected of the three and often the most relevant, because it is the only method that prices control. If a sale is a realistic outcome, this is the number that matters.
It is neglected because the data is difficult: deal terms are private, announced values include earn-outs that may never pay, and transactions age quickly. Handled properly it means quantifying the control premium rather than asserting it, adjusting for deal structure, and discarding anything older than about two years.
Present a range, not a number
The output of serious valuation work is a football field: each method's range shown separately, with a concluded range across them. Where the methods agree, you have a defensible position. Where they diverge sharply, that divergence is the most valuable output of the exercise — it usually means the market is pricing something your forecast does not reflect, or your forecast knows something the market does not.
Either way, that gap is what you should be able to explain. A single point estimate invites an argument about the point. A range with its reasoning attached moves the conversation to the assumptions, which is where you can actually win it.