Fixed-rate mortgages plunged dramatically this week.

The average 30-year fixed-rate fell 36 basis points, to 5.97 percent. A basis point is one-hundredth of a percentage point.

Rates tumbled after the Federal Reserve's Nov. 25 announcement that it will buy up to $500 billion of securitized loans.

The average 15-year fixed -- a popular option for refinancing -- also slid 26 basis points, to 5.75 percent. The average jumbo 30-year fixed sank 7 basis points, to 7.55 percent.

By contrast, adjustable-rate mortgages rose this week. The one-year adjustable-rate mortgage shot up by 39 basis points, to 6.17 percent. The popular 5/1 ARM increased 9 basis points, to 6.27 percent.

Meanwhile, mortgage loan activity grew by a seasonally adjusted 1.5 percent for the week ending Nov. 21, according to the Mortgage Bankers Association. The sampling period occurred before the Fed's announcement.

Refinancing activity actually fell 2.1 percent from the previous week, but applications for new purchase grew by 5.3 percent, according to the MBA.

This week's announcement that the Federal Reserve would buy up securitized home loans arrived on the heels of a trio of reports showing continued weakness in home prices and sales in recent months.

The S&P Case-Shiller home price index declined by a record 16.6 percent in the third quarter compared to the same period in 2007. The fall eclipsed the previous record dip of 15.1 percent set in the second quarter of this year.

Sales of existing homes also fell in October, slipping 3.1 percent from the September reading and 1.6 percent from the same period last year, according to the National Association of Realtors.

Finally, sales of new homes in October fell to their lowest level since January 1991, according to the Commerce Department. Sales were down 5.3 percent from September.

The national median existing-home price in October was $183,300, a decline of 11.3 percent from the $206,700 reading in October 2007, according to the NAR.

-- Chris Kissell

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