>It's because they're idiots who don't know when to quit. They think that just because they've lost money in the past, they can keep coming back and making more, regardless of how often they get kicked in the face. They're like lemmings following each other off a cliff. Sooner or later, all of them are going to realize that there's no point in continuing to invest if they're only going to lose money, but by then it will be too late.