Size-adjusting Volatility

Since the valuation of corporate securities with option-like features issued by the private companies requires an estimate of volatility based upon comparable public companies and the comparable companies are often larger, the use of unadjusted volatilities may understate the volatility of the subject private company. This article provides an up-to-date research review on the need for size-adjusting volatility. We also present a simple methodology to size adjust comparable companies that is easily updated with data contemporaneous to the valuation date.