Mortgage rates continued their seesaw ride, surging for the second time in three weeks.

The average 30-year fixed-rate rose 45 basis points, to 6.77 percent. A basis point is one-hundredth of a percentage point.

Last week, the 30-year fixed plunged 42 basis points -- that sharp decline coming just seven days after the 30-year fixed recorded its biggest weekly rise in the Bankrate.com index in more than 21 years. A basis point is one-hundredth of a percentage point.

In other mortgage rate news for this week, the average 15-year fixed -- a popular option for refinancing -- jumped a whopping 53 basis points, to 6.46 percent. The average jumbo 30-year fixed lept 30 basis points, to 7.95 percent.

The one-year adjustable-rate mortgage actually fell 5 basis points, to 6.09 percent. On the other hand, the popular 5/1 ARM rose 18 basis points, to 6.67 percent.

Mortgage activity rose for the third time in the past four weeks, according to the Mortgage Bankers Association.

For the week ending Oct. 24, mortgage activity rose a seasonally adjusted 16.6 percent. The week previous it fell the same 16.6 percent. Refinancing activity increased by 28.5 percent, while applications for new purchase grew by 8.5 percent.

Meanwhile, a pair of reports offered rare glimmers of hope for the beleaguered housing market.

Sales of existing homes rose by 1.4 percent in September when compared to the same time period a year ago, according to the National Association of Realtors.

In addition, sales of newly constructed homes grew by 2.7 percent in September when compared to August, according to the U.S. Census Bureau.

-- Chris Kissell

 See mortgage rates in your area.