This might be the first crack in the housing bubble. The graph below is of the Philadelphia Housing Index (major home builders) since the index began in 2002. The HGX index (In blue) has remained above the IndexÂ´s 200 day moving average line (in red) until very recently. This "technical" sign is not surprising given the increase in interest rates by the Fed and in long term governmen bonds. The index shows a 150% gain in the last couple of years, but several of the home builders are up much more since the housing bubble began.