Baltic Dry Index. Source: Lloyd's List. The Baltic Dry Index (BDI) is a measure of the price of shipping major raw materials such as metals, grains, and fossil fuels by sea. It is created by the London Baltic Exchange based on daily assessments from a panel of shipbrokers. The BDI is a composite of 3 sub-indices, each covering a different carrier size: Capesize, Panamax, and Supramax. Capesize carriers are the largest ships with a capacity greater than 150,000 DWT. Panamax refers to the maximum size allowed for ships travelling through the Panama Canal, typically 65,000 - 80,000 DWT. The Supramax Index covers carriers with a capacity of 50,000 - 60,000 DWT.