A ticker symbol is a unique series of letters assigned to a publicly traded company's stock or other security. It serves as a shorthand identifier for investors and traders to easily recognize and track the performance of a specific asset on stock exchanges like the New York Stock Exchange or NASDAQ. For example, the ticker symbol for Apple Inc. is AAPL. Ticker symbols can vary in length, typically ranging from one to five letters. They are essential for executing trades and accessing financial information, as they help differentiate between companies with similar names. Each symbol is unique to its respective company, ensuring clarity in the financial markets.