FIX-3-3 is an information technology protocol that enables users to exchange data over a variety of systems in a secure and reliable manner. The FIX-3-3 protocol was developed by the Financial Information Exchange (FIX) Working Group in 2009 and is the most widely used messaging protocol in the financial services industry. The protocol is based on the ISO15022 standard and is used by banks, brokerage firms, trade-processing systems, and exchanges, as well as other financial institutions to securely exchange data. It is used primarily in trading applications, including equity and options trading, forex, and derivatives trading. The protocol is designed to ensure that data is sent securely between entities and is designed to ensure that information is sent securely between systems. The protocol is used to facilitate electronic document exchange, electronic communication, and the secure transfer of financial information.