In business valuation, few assumptions matter as much—or cause as many disputes—as the discount rate.
To many non-experts, it can sound like a technical footnote. In reality, the discount rate often determines whether a business is worth $3 million or $5 million, whether damages are reasonable or overstated, and whether an expert’s opinion is accepted or challenged.
In 2026, discount rates are under more scrutiny than they have been in years. Courts, attorneys, and opposing experts are paying close attention, not because valuation theory has changed, but because the economic environment has.
What a Discount Rate Is (Without the Jargon)
A discount rate answers a simple question: What return would a reasonable investor require to take on this business, with its specific risks, today?
That rate reflects the time value of money, the uncertainty of future cash flows, and the risks unique to the business and its industry.
In practice, valuation professionals usually estimate discount rates using established frameworks such as: The Capital Asset Pricing Model (CAPM), The Build‑Up Method, and The Weighted Average Cost of Capital (WACC). Courts generally accept these methods. What they question is how the inputs were selected and applied.
Why Discount Rates Matter More in 2026
Interest rates are no longer background noise. After years of near-zero rates, today’s environment makes discount rates central drivers of value. Currently, interest rates remain higher than most of the past decade, borrowing costs vary widely depending on company size and credit quality, and investors are more sensitive to risk and uncertainty; as a result, discount rates are no longer passive assumptions. They are active drivers of value.
Small changes can mean big money. A 1% change in the discount rate can shift value by 10% or more, often translating for a closely held business into hundreds of thousands or millions of dollars. That difference often exceeds the combined impact of disputes over growth rates, normalization adjustments, or even methodology selection.
Where Discount Rate Disputes Arise
Discount rate disputes commonly appear in divorce matters, shareholder disputes, and lost profits cases. These disputes often focus on unsupported risk premiums, inconsistent assumptions, and outcome-driven adjustments.
Common Discount Rate Problems
Across litigation and contested valuations, the same issues appear repeatedly; this includes but not limited to: relying on published data without company‑specific analysis, layering multiple risk premiums without explaining overlap, reusing discount rates from prior valuations without reconsideration, applying aggressive growth assumptions alongside high risk premiums, and treating discount rate selection as a formula exercise rather than judgment. When these issues appear, credibility, not just math comes into question.
What Courts Are Looking For
Courts are not searching for a single correct discount rate. They are looking for transparency, consistency, current market support, and independent professional judgment. In short, courts want to understand how the expert thought, not just what number they chose.
Practical Takeaways
Discount rate assumptions should be addressed early, supported clearly, and explained in plain language. When handled properly, they reduce disputes. When handled poorly, they become credibility issues.
Judgment Still
Discount rates are not just some technical details buried in an appendix. They can be the center of the valuation debate. Whether the matter involves divorce, shareholder conflict, damages, or planning, a defensible discount rate requires awareness of current economic conditions, discipline in applying accepted methods, and independence from the desired outcome. When those elements are missing, valuation disputes often turn into credibility disputes—and credibility is difficult to recover once lost.
Professional Disclaimer
This article is for educational purposes only and does not constitute legal, tax, or investment advice.