FIX-3-10 is a set of rules, messages, and session categories which are part of the Financial Information eXchange (FIX) protocol for computer-based electronic trading in the financial markets. FIX-3-10 defines the standard for messages used for topics such as market data, order entry, order modifications, executions (trades and trade cancelations), and more. Additionally, FIX-3-10 defines the standards for launch sequences, error checks, heartbeats, and other control mechanisms of FIX sessions.