What are contract trading codes?

Contract codes are often one to three letter codes identifying the asset that is attached to a specific contract. For example, E-mini S&P 500 futures' contract code is ES. Make note that these codes could vary across platforms. Following the contract code should be a letter and a number, for example, ESM5. The M represents a month (June) and the 5 represents a year (2025). Each month has its own letter. So, as in the example listed above, ESM5 would represent an E-mini S&P 500 futures contract expiring in June 2025.