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

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 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, Bloomberg said.

“We’re getting more activity, more traffic and even pricing has begun to improve,” said Jason Benowitz, portfolio manager for Roosevelt Investments in New York.

Shares rallied as new homes sold at a seasonally adjusted annual rate of 350,000 in June, about half the 40-year average, according to U.S. Commerce Department data. That’s still an improvement over 304,000 in June 2011 — enough to help engender a big rebound for home builders, which underperformed the S&P 500 from 2005 through 2011.

PulteGroup Inc. has jumped 98 percent this year, Lennar Corp. is up 59 percent, Toll Bros. Inc. rose 49 percent and D.R. Horton Inc. has increased 43 percent.

The annual equivalent returns for the S&P homebuilding index so far in 2012 would be more than 100 percent, the best for any year in data going back to 1995. The index lost 87 percent from a peak in 2005 to its low in November 2008, Bloomberg said.