Buying a house is really

investing using lots of leverage. You put down a small percentage and get a loan several times larger. It is kind of like buying stocks on margin. The difference is of course - one, you live in the house, two, the house is not as liquid, people don't buy and sale as often as with stocks. But still it is a lot of leverage. Which means if the market goes up, you small downpayment as investment gets high returns, but when the market goes down, you loose big too-unless you tough it out by keeping up the mortgage payments and wait it out until the market recovers-which can take many years. People were known to just give up and walk out of the house when they can not keep up the mortgage payments.

Bottom line is like buying stocks you have to gauge your ability to take risks. There is no garantee that the housing market is only a one way up steet.