Run Time: 36.36 minutes Kent Osband, Founder of RiskTick LLC, a consultancy tracking financial turbulence philosophizes that like the atmosphere or the seas, financial markets sometimes get so stirred up that it seems like angry spirits must be stirring them. In fact, any sufficiently abrupt change in beliefs -- including from perfectly rational learning -- is bound to trigger major uncertainty, disagreement and market turbulence:

- Turbulence limits predictability and can make perfectly rational investors look foolish.
- Turbulence has merits too: without it we might...