James Thurber and E.B. White wrote a book called Is Sex Necessary? We now know the answer to that: No. Technology allows conception to take place by other means, although there are good reasons why people still use the tried and trusted method.

The flurry of mergers and takeovers on Wall Street prompts an analogous question: are stock exchanges necessary? The fact that securities trading is still mostly done on trading floors, or via electronic exchanges, does not mean it has to be this way. Two investors in search of a well-matched trading partner can have a tryst by other means.