The reference text on private-company valuation. Academic in register. Damodaran's chapters on private-company illiquidity discounts, key-person discounts, and growth-rate sensitivities are the empirical anchor most other operator-facing books reference without naming.
Most founders will not read Damodaran cover to cover. Most founders should read the chapters on private-company adjustments, the discount stack, and the section on the illiquidity discount. These chapters explain the math underneath the discount patterns founders encounter in real transactions but rarely see explained outside of academic settings.
The supporting material on Damodaran’s NYU Stern website (data sets, lecture notes, valuation models) is also useful and free.
Read for: chapters 24 through 26 on private-company valuation specifically. Read past: most of the public-equity chapters unless you have a specific reason.