When stock prices go all wonky, as they have in recent days, it pays to think a little about what really moves asset prices and determines long term business success. For ConvergEx’s Nick Colas, the key driver has been – and always will be – return on capital. What investment analysts know as the DuPont model is now 100 years old, but its lessons and applications still drive innovation today. Want to know why Airbnb or Uber are successful?