There are differences between this run-up in prices and the housing bubble that preceded the financial crisis, said Gary Thomas, the National Association of Realtors' president.

"The boom period was marked by easy credit and overbuilding, but today we have tight mortgage credit and widespread shortages of homes for sale," Thomas said. The improved housing market and mortgage rates still near record lows, despite a recent rise in rates, is pulling buyers back in the market faster than it's prompting sellers to put homes on the market. Buyer traffic 29% above a year ago, but the supply of homes for sale is actually down 10%, writes CNNMoney.