As US markets wrapped up their worst monthly performance so far for 2013, financial stocks lost their leadership role to basic materials. The materials sector was the most strongly performing segment of the S&P 500 during August and in July and August combined. The financial sector which has been the strongest performing part of the market over the last 12 months was the weakest sector in August. The broader US market has been spooked by the idea that the Federal Reserve is going to taper its securities purchases in the coming few weeks. At the same time, evidence of better global growth has been accumulating including from the USA where the second quarter GDP growth estimate was revised up on Thursday. S&P 500 constituents copper/gold miner Freeport McMoran and iron ore miner Cliffs Natural Resources both added 6.9% during August.