Unlike sharp declines in the past, the Flash Crash happened for apparently no reason. Since then the government has launched multiple inquiries into what happened and recently charged a trader for alleged market manipulation. Figuring all of this out is considered a priority because the stock market is an important part of the economy and has an important place in economic policy.

But does the stock market really matter? And if it does, should it?

Stock market relevance to policy dates back to the crash of 1987, when Fed Chairman Alan Greenspan decided the Fed should respond boldly to market machinations. That emphasis on the importance of stocks was at the core of the Greenspan Fed and was continued by his successors Ben Bernanke and Janet Yellen.