The FRED series Total Credit Market Assets Held by Domestic Financial Sectors is now known as Financial Business; Debt Securities and Loans; Asset, Level.
The source series id is FL794004005.Q.
The series previously appeared in Table L.1, but is updated in the underlying data set. For further information see the assistance provided in the guide to the Financial Accounts at http://www.federalreserve.gov/apps/fof/.
Board of Governors of the Federal Reserve System (US), Financial Business; Debt Securities and Loans; Asset, Level [TCMAHDFS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/TCMAHDFS, February 21, 2019.