What is the mapping in the file?
The securityId field is the positive integer value used in the MEMOIR feeds when market data updates are reported for the product. The symbol field is a string that contains the CMS Symbol Root for the product. The symbolSfx field is a string that contains CMS Symbol Suffix for the product. The roundLot size is a integer that contains the round lot size for the product. The isTestSymbol field is a boolean field that indicates if the product is a test symbol to not. The mpv field is an integer field that indicated the minimum price variation for the product. The mpv is specified as a fixed-point scaled decimal with 6 implied decimal digits. For example an mpv of $0.01 appears as 10000 (representing 0.010000).
Will the mapping of an existing securityId to symbol ever change?
A given symbol to securityId mapping will not change. Additional symbols will map to new securityIds.
When is the file posted each day?
The file is typically posted at ~6AM Eastern Time.
If there is an intraday update, will that be reflected in the file?
The file can be updated after initial posting if there are intraday changes.
How do I know when the file was last updated?
The end user is responsible for discovering daily and intraday deltas.