Roughly 10 million refinances took place over the past two years, although that may include borrowers who have refinanced more than once, according to Inside Mortgage Finance. From mid-2011 to mid-2012, rates dropped by 100 basis points, making it worthwhile for some to refinance more than once.In addition to low rates, the government's refinance program, called HARP, for underwater borrowers with Fannie Mae and Freddie Mac loans, helped juice refinances as well.
In the first three months of this year, there were nearly 1.4 million refinances on Fannie Mae and Freddie Mac mortgages alone, according to the Federal Housing Finance Agency. Of those, 22 percent were through HARP, which was recently extended through 2015. More than 2.4 million borrowers so far have taken advantage of that program.
For borrowers who don't have government-backed loans and therefore don't qualify for that program, rising home prices have helped allow more of them to qualify for refinances. Among borrowers, 850,000 rose above water on their mortgages, moving into a positive equity position in the first three months of this year, according to a new report from CoreLogic. While nearly 10 million are still underwater, the more that rise above, the more refinances can happen.
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"We are still far below peak home price levels, but tight supplies in many areas coupled with continued demand for single family homes should help us close the gap," said Anand Nallathambi, the CEO of CoreLogic.
Rising prices, however, are a double-edged sword, especially in a rising interest rate environment. Potential buyers are losing purchasing power every day, just as demand is surging.
—By CNBC's Diana Olick. Follow her on Twitter
@Diana_Olick or on Facebook at facebook.com/DianaOlickCNBC.
Questions? Comments? RealtyCheck@cnbc.com.