Symbol Suffix

A symbol suffix is the tag a broker appends to an instrument name to separate account types or price feeds — EURUSD.m, EURUSDpro, EURUSD.raw, XAUUSD_ecn. It is housekeeping on the broker's server and stays invisible right up until something automated has to match the name exactly. That is where it bites. Expert advisors, copy-trading links and signal services frequently hard-code the plain symbol, so identical code that runs on one server silently opens nothing on another, or opens on the wrong contract entirely. Backtests inherit the same fault when history is stored under one name and live quotes arrive under another. Before deploying anything automated, read the exact symbol string out of Market Watch instead of assuming it, and open the contract specification behind it to confirm the size and margin match what you expect.