U.S. home-builder shares are appreciating at a record rate this year, reflecting confidence the housing rebound from a six-year slump can accelerate with new-home sales still 50 percent below the 40-year average.

The Standard & Poor’s Supercomposite Homebuilder Index of 11 companies has climbed 53 percent this year through Aug. 10, compared with a 12 percent gain for the broader S&P 500 Index. Builders, including PulteGroup Inc. and D.R. Horton Inc., are raising prices in markets with limited inventory and targeting move-up buyers with more money for down payments and better access to credit than first-time purchasers.