The U.S. spends 8 percent of its GDP on finance -- twice the amount it did 40 years ago, according to economist Brad DeLong. That figure set off a wave of soul-searching recently as commentators asked how ``the financialization of the world'' came to be and others attempting to answer that very question. This week, we speak with Satyajit Das about how finance took over the economy, markets and monetary policy. A former banker, trader and corporate treasurer, Das is well-placed to walk us through the development of global financialization and its pitfalls. Along the way we talk bonuses, negative interest rates, home safes and (of course!) alien invasions.