NEW YORK ( TheStreet) -- This is my fourth installment of articles covering the housing market and banking system based upon the FDIC Quarterly Banking Profile for the second quarter of 2013, ValuEngine data, technical analysis and my proprietary analytics.On Monday I wrote, JP Morgan Upgraded As Banking System Heals where I summarized the evolution of the housing bubble and how the bursting of the bubble created toxic assets throughout the banking system resulting in the Great Credit Crunch. In this post I profiled the four 'too big to fail' money center banks. Also on Monday I wrote, Housing Bubble Is Re-inflatingwhere I explained how the homebuilders led the 2013 stock market rally into May 20 and have since lagged as home prices and mortgage rates moved higher. I profiled the 11 homebuilder stocks and today DR Horton ( DHI), M/I Homes ( MHO), PulteGroup ( PHM) and Toll Brothers ( TOL) have been downgraded to sell from hold according to www.ValuEngine.com. On Tuesday I wrote, Bank Earnings Rise, but Not Real Estate Lending where I sliced and diced the real estate related assets shown in the FDIC Quarterly Banking Profile. The banking system may appear healthier on the surface, but crunch issues remain such as; a decline of $1.8 billion in interest income, and a negative mark-to-market of $51.1 billion on fixed income securities in holdings classified as 'available for sale' securities. Since the end of 2007, other real estate owned is up 168.6% at $32.6 billion. Reserves for losses are elevated by 46.5% at $149 billion. And, noncurrent loans are up 117.7% at $239.3 billion. BAC), JPMorgan ( JPM) and Wells Fargo ( WFC) are experiencing reduced demand for mortgages as mortgage rates rise.