A typical financial analyst has dozens of data sources that he is looking at to make decisions. They will be looking at news feeds, time series charts with company metrics, biographical data on company officers, regulatory filings and increasingly multimedia sources like talk shows and news broadcasts. The problem is that each one of these data sources is stored in a different format in a different system that is optimized for managing and analyzing that particular kind of data.
For example. news feeds may be stored in a searchable database on a site like Bloomberg or Reuters. Securities metrics may be stored in a separate structured data store, and regulatory information will be filed with the SEC in EDGAR format. All of this information is about the same broad subject area, but none of it is linked together.