I need to do symbology translations between two financial systems. One part of this is to identify a symbol that is an index in one system so that I can prepend a character to it when I send it to the other. The first system does not use any special formatting to indicate that a symbol is an index.
To do this I need to find a list of all US Indices so I can classify a symbol via a lookup. At minimum I need an index's symbol but I would also like to have its CUSIP and Name. Ideally it would be a data source that is updated on a regular basis that I can programmatically pull from.
Does anyone know a good data source for US Indices? Free is always good!