U.S. stocks and exchange traded funds (ETFs) started out strong on news of additional financial aid for Greece; however, unfavorable U.S. economic data restrained additional gains.

The SPDR S&P 500 ETF (NYSEArca: SPY) is down 1.59% over the past month and is currently up 0.62%.

The S&P/Case-Shiller composite index of 20 major U.S. cities dropped 0.8% in March on a non-seasonally adjusted basis, with prices in 18 of 20 cities dropping on a monthly basis, reports Greg Robb for MarketWatch. Prices declined 3.6% year-over-year in March, and the index has reached a double-dip downturn after retreating past April 2009 lows. [Greece Bailout Catapults Stock ETFs Higher.]

SPDR S&P Homebuilders (NYSEArca: XHB) is up 0.91% and the iShares Dow Jones U.S. Home Construction (NYSEArca: ITB) is up 1.2%.

The housing market is currently suffering from a glut in distressed properties, a “shadow inventory” of houses, which has made sellers loathe to dump their properties, and a reduced number of consumers who are qualified for mortgages.

Lou Crandall, chief economist at Wrightson ICAP, opines that home prices will experience a negative 4% year-over-year nadir during the summer season.