BDI. Index established by the London-based Baltic Exchange for tracking dry bulk shipping and trading costs. This is comprised of three sub-indices which are subdivided by the different categories of bulk ships (Capesize, Supramax or Panamax). The BDI was established in order to calculate costs in transporting raw materials. It can be volatile due to the high costs of transporting and its high susceptibility to global demand but low susceptibility to speculation. For this reason, investors look to the BDI as one possible gauge of future economic growth. also called Dry Bulk Index.