Refining and Selecting the Appropriate DLOM The discount for lack of marketability (DLOM) is the result of illiquidity. It represents the inability to sell quickly when an investor decides to sell an asset. It is the economic cost of failing to realize gains or to avoid losses during the time period that the investor or closely held business owner is trying to sell the asset or securities. In this article, Marc Vianello describes an approach he describes as more “refined” than other methods for estimating DLOM.