Volatility remains the name of the game for mortgage rates, which plunged this week.

The average 30-year fixed-rate dropped 33 basis points, to 6.44 percent. A basis point is one-hundredth of a percentage point.

Since Oct. 1, mortgage rates have moved at least 20 basis points each week. During that time, they've remained in a pattern of falling sharply one week before rising dramatically the next.

The average 15-year fixed -- a popular option for refinancing -- plummeted 25 basis points, to 6.21 percent. The average jumbo 30-year fixed skidded 19 basis points, to 7.76 percent.

The one-year adjustable-rate mortgage slid 24 basis points, to 5.85 percent. The popular 5/1 ARM fell 21 basis points, to 6.46 percent.

Mortgage activity slipped for the week ending Oct. 31, according to the Mortgage Bankers Association.

Mortgage activity fell a seasonally adjusted 20.3 percent from one week earlier. Refinancing activity fell 27.8 percent, while applications for new purchases slid 13.9 percent.

In other housing news, JPMorgan Chase announced plans to modify up to $70 billion in mortgage loans to help prevent 400,000 homeowners from falling into foreclosure. The new effort builds on $40 billion in earlier loan modifications by JPMorgan.

Other lenders -- including Citigroup and Bank of America -- also have implemented loan modification programs designed to help at-risk homeowners remain in their homes.

In recent days, there has been speculation that the federal government may guarantee mortgages in an attempt to prevent a wave of new foreclosures.

The Federal Deposit Insurance Corp. and the Treasury Department are said to be working on a plan to use up to $50 billion from the recent bailout package to shore up millions of at-risk mortgages.

However, the plan is controversial and is reported to be just one option among several currently under review.

-- Chris Kissell

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