However, Dimon cautioned, "You never saw losses in these products, because home prices were going up."
The sector's failure, he added, was the assumption that prices can only go up.
By 2006 there were plenty of reasons that the existence of a housing bubble was rather obvious, even if all the details weren't known yet and the eventual consequences weren't completely clear.
My main reason, a rather simple one, was that not nearly enough people had the kind of incomes that allowed them to afford homes at those prices. I know that because the helicopter is not my primary mode of transportation.