U.S. Rep. Barney Frank, D-Massachusetts and Chairman of the House Financial Services Committee, Thursday introduced legislation to enable the Federal Housing Administration to insure and guarantee mortgages that have been written down banks and other mortgage holders, Rep. Frank announced in a statement.

Rep. Frank's proposal would permit the FHA to provide up to $300 billion in loan guarantees which could potentially result in the refinance of 1-2 million at-risk mortgages, preventing foreclosures, "protecting neighborhoods and help stabilize the housing market."

Barclays analysts say banks that obtained $72 billion in funding to replenish capital depleted by subprime-related losses may need another $143 billion in capital infusions if credit rating agencies downgrade bond insurers several levels, Bloomberg News reported Friday.

Barclays analyst Paul Fenner-Leitao Banks wrote in a research report published Friday that banks will need at least $22 billion if bonds covered by insurers MBIA (NYSE: MBI) and Ambac (NYSE: ABK) are cut one level from the current AAA and six times that if they are cut four levels, Bloomberg said. The capital amount is based on Barclays' estimates that the banks hold as much as 75% of the $820 billion of the structured securities guaranteed by bond insurers.

Meanwhile, the markets awaited word on New York Insurance Superintendent Eric Dinallo's meeting with banks on a bail-out package for bond insurers. Shares of some key bond insurers fell after Dinallo issued a statement that the negotiations were complicated and would take time, leading some in the market to doubt the New York agency's ability to marshal private resources for the initiative.

MBIA fell 79 cents to $13.61, Ambac gained 15 cents to $11.48, PMI Group (NYSE: PMI) rose 17 cents to $8.97, and MGIC Investment (NYSE: MTG) declined 6 cents to $16.68.

Given the U.S. market's 400-point sell-off in its initial minutes of trading, "a Dow close down just 300-points would look like a moral victory" according to one economist.

"All things considered, from a market standpoint, a 300-point down day is a relatively small consequence," economist David H. Wang told BloggingStocks Tuesday.

Amid the sell-off, the U.S. Federal Reserve, in an emergency monetary policy action, cut key interest rates Tuesday morning - - cutting both the Fed Funds rate and the discount rate by 75 basis points. The Fed cut the Fed Funds rate to 3.50% and the discount rate to 4.00%.

Larger matter: mortgage insurers

Of utmost importance, in Wang's interpretation, is the health and fate of mortgage insurers, primarily MBIA (NYSE: MBI), and Ambac (NYSE: ABK), but also PMI Group (NYSE: PMI), and MGIC (NYSE: MTG).

Wang said the mortgage insurers "form a critical foundation in mortgage insurance, and as a result, in the mortgage process."

"A failure by MBIA or Ambac would mean several banks would not receive insurance payments for mortgages that go into default, substantially reducing the asset values of those banks," Wang said. "That would prompt another market sell off, possibly resulting in a failure by one or more banks."

Further, the move is the largest coordinated international monetary policy action taken since the world's major central banks provided liquidity to ensure proper market function following the September 11, 2001, terrorist attack on the United States.

The Fed announced Wednesday that it would inject up to $40 billion in reserves into money markets via a new, temporary program called a "term-auction facility." The emergency funds would be made available to banks next week via auction process -- $20 billion each -- on December 17 and December 20. The Fed also said it is setting up lines of credit with the European Central Bank and the Swiss Central Bank that could be used for additional resources.

Most investors and readers are aware of the subprime mortgage-driven credit market slump. Lending to potential customers has declined substantially, from typical homebuyers to large corporations.

To be sure, the credit markets are not frozen, as they appeared to be during the August 2007 credit crunch and accompanying equity market sell-off, but lending requirements are much more rigorous today, following large subprime investment losses.

Speculative deals -- be it a large debt offering backed by mortgages, or a mortgage for a condominium project -- are not being approved. Two years or so ago, flush with cash and eager to take advantage of the yield spread, these type of deals undoubtedly would have received multiple funding offers from banks, mortgage companies, and other investment firms.

Another day, another huge decline in the Dow Jones Industrial Average.

Stocks tumbled yet again today as widespread panic over subprime mortgages, worries over retail sales and general unease about the future caused investors to shift their money into safe havens such as mattresses, refrigerators and crawlspaces in their homes. Pleas for calm by pundits such as Citigroup Inc. (NYSE:C) strategist Tobias Levkovich, who today urged investors "not to succumb to an emotional desire to sell before things get worse" were ignored.

What's remarkable about this more than 100 point sell-off is that it came after the Fed pumped $24 billion in temporary funds into the economy. Central banks in Japan, Europe and Australia also responded to the crisis, according to Bloomberg News.

Still, the market isn't stable and bad signs abound.

Countrywide Financial Corp. (NYSE: CFC) scared the bejesus out of the market yesterday with its warning of "unprecedented disruptions." France's BNP Paribas froze three investment funds that until fairly recently were worth about $2.2 billion because of losses in the U.S. mortgage market and apartment builder Tarragon Corp (NASDAQ: TARR) raised doubts about its ability to continue in business, according to the Wall Street Journal.

About the only good news came from the Fed's declaration this morning that it would provide liquidity "as necessary" to bolster the market.

Smart investors know that it's always darkest before the dawn, but that doesn't make times any less dark.