QE. All the low risk high quality debt is effectively cleared by governments in order to 'stimulate' the economy. Well, after enough years of pumping enough sti

QE. All the low risk high quality debt is effectively cleared by governments in order to 'stimulate' the economy. Well, after enough years of pumping enough stimulus in, the economy starts to look like someone on a perma-high who can't come down. That's what we're seeing here: totally irrational behaviour caused by an apparently endless supply of free money. Track it back far enough and you end up at the central bank.