Many of the proposals in this Symposium (and in the halls of legislatures and regulatory agencies) take the form: "Stock prices can be inaccurate, so financial markets therefore do not always induce managers to act in investors' best interests; therefore we should impose on managers the following governance rules ..... With markets in derivatives producing the information that short sales in stock markets have been unable to produce, arguments of this stripe should fade into history. It is impossible to see how legislators, regulators, or judges could claim a comparative advantage over financial markets once trading in derivatives ensures that all public information is embedded in securities prices.