The Flow of Funds Accounts are a crucial data source on credit market positions in the U.S. economy. In particular, they combine regulatory data from various sources to produce a consistent set of flow and stock tables in major credit market instruments by sector. The events of the last five years have underscored the importance of positions data to guide economic analysis. Viewing positions as payment streams typically requires more information than book value or fair value. However, much of this information is already contained in the data sets from which the Flow of Funds accounts are constructed. This chapter first argues that quantitative analysis of credit market positions would benefit tremendously if the additional information about the structure of payment streams were more readily available, and derives some concrete alternatives for data collection.