Financial markets today are the biggest markets in the world. The foreign exchange market turns over US$1.2 trillion daily, roughly one quarter of annual world exports. The regulation of financial markets therefore concerns us all. This paper covers the What, Why, Who and How of financial regulation. Financial markets engage in the exchange of property rights. Financial assets are derivatives of physical or real assets, derivatives being property rights of property rights that are not “lumpy” or asset specific, and transactions  costs in them being lower than transactions in real assets