The term AMEX UNIT is composed of four words: SEC, COS, SHR, and SHARE. SEC stands for Securities and Exchange Commission, which is a government agency that regulates the stock market and other financial activities. COS stands for Chief Operating Officer, which is a senior executive responsible for managing the day-to-day operations of a company. SHR stands for SHARE, which is a unit of ownership in a company. Finally, SHARE stands for Stockholder's Rights to Appreciate Equity, which is a type of stock option that allows shareholders to benefit from the appreciation of the company's stock.