What banana art says about Federal Reserve policy

Did you hear the one about the $6.2 million banana? That’s the price a piece of art consisting of a banana duct-taped to a wall fetched this week, up from a "mere" $120,000 it sold for five years ago. Why it matters: It is a fitting metaphor for an exuberant, and frothy, moment in financial markets of all types, one that raises uncomfortable questions about whether Federal Reserve…