Ethics and efficiency in Islamic stock markets

In an Islamic stock market, concerns about ethics and values must be taken into account. Regulators and potential investors often worry that this will take place at the expense of efficiency. No trade off has to exist between Islamic values and efficiency. This is due, in part, to a partial and incorrect definition of efficiency. Islamic ethical norms, such as freedom from riba, gharar, ghubn, jahalah, etc. ensure efficiency.