For the most part, these investors lost, because when interest rates fell in 1993, many people refinanced their mortgages and paid off the original loans.

A family's average tenure in a home, he said, is seven to nine years, "and as interest rates go up and down, people refinance."

"If people can refinance their mortgage, that really puts money in their pockets," he said.

Lately, the turnover has been even faster, as people refinance.

"The lenders are thinking so many people have refinanced, that there's not much market left for them," he said.

"Some people refinance based on the promise that in a year or two they'll get a better rate," she said.

The first couple of reasons people refinance that I mentioned above are very self explanatory.

With interest rates dropping last year, many people refinanced mortgages to get the lower rate.

But people aren't refinancing mortgages to free up cash for other spending, as they did in 1993.

This is important because many people have frequently refinanced the loans they used to buy the house.