Forecasted ending stocks for corn could result in a 39 day supply if stocks from China and the U.S. are removed, which would be the same level it was at six years ago when corn prices spiked to a record of more than $8 per bushel.Prices could start to rise if an expected 159 million tonnes of ending stocks materializes by the end of 2018-19. Global corn stocks are finally starting to tighten up. U.S. Department of Agriculture forecasts 159 million tonnes of world ending stocks by the end of 2018-19. That is a 53-day supply of the crop.