FIX Error: Missing Symbol (55) – How to Fix
Tag 55 (Symbol) identifies the security being traded. This field is mandatory for all order messages and execution reports. Without it, the broker cannot identify which instrument to trade.
Root Cause
1) Symbol not captured from order entry, 2) Message builder omits Symbol field, 3) Symbol lookup fails, 4) Empty or null symbol value.
Broker/Exchange Action
Broker rejects with RefTagID=55, SessionRejectReason=6. Order is not accepted.
Client/Your Action
1) Ensure Symbol is captured from order entry, 2) Validate Symbol is non-empty, 3) Use correct symbol format (ticker, ISIN, etc.) per broker requirements, 4) Check symbol mapping tables.
Example FIX Message
How FIX Doctor Detects This
FIX Doctor checks all order messages for presence of tag 55. Missing Symbol triggers an error.
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