NEW YORK ( ETF Expert) -- Americans are at it again. They are becoming wide-eyed at the prospect of real estate riches, convinced by media cheer-leading that the 2007-2009 collapse in home prices was a once-in-a-century anomaly.Why shouldn't we be enthusiastic? Home values have been rising by double-digit percentages. Buyers are tripping over themselves to outbid one another. When the vast majority of participants still fail to understand leverage, they are easily persuaded by the promise of 100% paper gains on 20% down. Yet, the stock market has a way of detecting problems long before they start. Take a look at 2007 -- a year when the stock market eked out a respectable gain on low volatility, but the SPDR Sector Select Financial Fund ( XLF) had declined dramatically. In essence, the investment community had already sniffed out the flattening of real estate prices, the waning of housing affordability and the bursting of a mortgage bubble.