This paper studies the factors that cause difference in fluctuations of home price indices across the five regions of U.S. The factors that affect the home price index are not the same for all the five regions of the U.S.A. - West, Southwest, Midwest, Northeast, and Southeast. Additionally, not all the factors contributing to the home price index in a particular region remain significant contributors always. Finally, the extent of impact the contributing factors cast on the home price index fluctuations also change overtime. So, in this paper, I have determined which factors play role in determining the home price index fluctuations in each state. Then I have developed a comparative analysis on which factors play more significant role in determining the home price index fluctuations in each state. Finally, I forecasted the home price index fluctuations in each state for four quarters. After I finished all the analyses and made all the relevant forecasts, I came up with the conclusion that among all the independent variables, percentage change in income is the most important factor in determining the home price index fluctuations. GDP Growth Rate and Inflation play role too, but in a limited manner. However, interest rate and unemployment rate are the least influential factors in determining the home price index fluctuations.