Those commodity markets recently experiencing precipitous price falls have had one thing in common: large gaps between prevailing prices and production costs

John Robertson is Chief Investment Strategist for PortfolioDirect a provider of resource sector investment stock ratings and portfolio strategies for mining and oil and gas investors. He has worked as a policy economist, corporate business strategist and investment market professional for over 30 years after starting his career as a Commonwealth Treasury economist in Canberra. Since being Australia's top-rated commodities analyst and chief economist at one of Australia' leading stockbroking firms, he has advised companies across the mining, consumer products, IT and biotech sectors on their equity market relations. He leads the firm's investment evaluation and security structuring activities on behalf of the Australian Small Scale Offerings Board (ASSOB), the world's first equity 'crowdfunding' investment platform. John Robertson discusses the interaction of mining and investment markets in his weekly 'From the Capital' column in Mining Journal.