The term WALL ST. ABBR. refers to abbreviations commonly used in the Wall Street financial district. The four abbreviations are AMEX (4 letters), which stands for American Stock Exchange; RTS (3 letters), which stands for Real-Time System; SHR (3 letters), which stands for Share; and NYSE (4 letters), which stands for New York Stock Exchange. These abbreviations are used to refer to the various stock exchanges and systems that are part of the Wall Street financial district.