January 27, 2009Rex Nutting MarketWatch Pulse Buzz up! Digg It StumbleUpon Reddit WASHINGTON — Home values in 20 major U.S. cities fell at a record 18.2% in the 12 months ending in November, Standard & Poor’s reported Tuesday. The Case-Shiller 20-city home price index fell 2.2% in November, with home values in all 20 cities falling at least 1%. Prices fell 3.4% in Phoenix and 3.3% in Las Vegas in November. In the past year, prices were down 33% in Phoenix, 32% in Las Vegas, and 31% in San Francisco. The best performance over the past year came in Dallas, where prices fell just 3.3%. Falling home values have helped to plunge the global financial system into chaos because of mortgage-backed securities. Home owners have lost trillions of dollars of wealth. Hopefully, like Northern Virginia, home prices will fall to a level that will bring buyers back into the market. Housing inventory there has dropped from 10 months last year to 5 months currently. Copyright © 2009 MarketWatch, Inc.