Sensitivity Analysis: Stress-Testing Your Valuation Like a Pro
A single-point DCF output is almost never useful on its own. Any valuation is only as credible as the assumptions behind it, and those assumptions are inherently uncertain. Sensitivity analysis addresses this by showing how the output changes across a range of input values, giving you (and your audience) a clear picture of what really drives the valuation.
The most common sensitivity table in equity research is the WACC vs. terminal growth rate matrix. On one axis, vary the discount rate from, say, 7% to 11%. On the other, vary the perpetuity growth rate from 1% to 4%. The resulting grid shows implied share prices for every combination, immediately highlighting which assumptions matter most.
Beyond the standard WACC/growth table, consider building sensitivities around your most uncertain operating assumptions. Revenue growth rate vs. operating margin is a powerful combination for growth companies. For capital-intensive businesses, capex intensity vs. WACC can be more revealing. The key is to focus on the two or three variables that your thesis depends on.
When presenting sensitivity analysis, use color coding to make the output intuitive. Green for scenarios where the stock is undervalued relative to the current price, red for overvalued, and neutral tones for the base case. This allows readers to instantly see the risk-reward skew without parsing a wall of numbers.
A well-constructed sensitivity table also serves as a reality check on your model. If a small change in WACC (say, 50 basis points) causes the implied share price to swing by 30% or more, your terminal value is probably too dominant in the valuation and you should revisit your explicit forecast period or terminal assumptions.
Finally, scenario analysis complements sensitivity analysis by packaging multiple assumption changes into coherent narratives (bull case, base case, bear case). Each scenario should tell a story -- not just change numbers randomly. The bull case might assume faster market share gains and margin expansion, while the bear case models competitive pressure and margin compression.