Mortgage rates  4.15. Freddie Mac released the results of its Primary Mortgage Market Survey (PMMS), showing mortgage rates, fixed and adjustable, reaching all-time record lows providing further incentive for those homeowners looking to refinance. The 30-year fixed-rate mortgage (FRM) averaged 4.15 percent with an average 0.7 point for the week ending Aug. 18, 2011, down from last week when it averaged 4.32 percent. Last year at this time, the 30-year FRM averaged 4.42 percent. The 30-year fixed average of 4.15 percent, breaks the previous record low of 4.17 percent set on Nov. 11, 2010.The 15-year FRM averaged 3.36 percent, with an average 0.6 point, down from last week's totals when it averaged 3.50 percent. Last year at this time, the 15-year FRM averaged 3.9 percent.

"The Federal Reserve's policy statement last week and ongoing market concerns over the European debt market carried momentum into this week allowing all mortgage products in our survey to reach all-time record lows," said Frank Nothaft, vice president and chief economist for Freddie Mac. "For instance, 30-year fixed mortgage rates are now the lowest in over 50 years. In comparison, the Bureau of Economic Analysis estimated the average effective mortgage rate was about 5.3 percent on single-family loans outstanding during the second quarter of 2011."

The five-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) averaged 3.08 percent this week, with an average 0.5 point, down from last week when it averaged 3.13 percent. A year ago, the five-year ARM averaged 3.56 percent. The one-year Treasury-indexed ARM averaged 2.86 percent this week with an average 0.6 point, down from last week when it averaged 2.89 percent. At this time last year, the one-year ARM averaged 3.53 percent.

"Not surprising, many homeowners took advantage of this low mortgage rate environment and have already refinanced their loans," said Nothaft. "The refinance share of applications averaged nearly 70 percent of all mortgage activity in the first half of this year, according to our survey. In addition, an increasing share of refinancing borrowers chose to shorten their loan terms during the second quarter, according to Freddie Mac's Quarterly Product Transition Report."