This study compares trading prices of unregistered stocks of publicly traded companies (whose trading was restricted by SEC Rule 144) against sister stocks in the same company that were registered with the SEC and publicly traded. The difference in prices between the unregistered "restricted stock" and the registered stock is called a “discount for lack of marketability” ("DLOM"). Business appraisers often use the study as a benchmark for estimating the DLOM component of value associated with closely-held, noncontrolling (often minority) business ownership interests.