Trade requires information. Buyers and sellers need to know the attributes of goods. Merchants with contracts need to know whether other parties are complying. Principals need to know what agents are doing. Traders in general want to transform uncertainty about the future into risk – to move from being unable to ascertain the probability of a particular event to being able to predict and thus prepare for it. To plan business dealings, merchants need to know about price movements, supply chains, demand conditions, political developments, military events, geographical obstacles, weather patterns, commercial techniques, foreign languages and alien customs.

The medieval and early modern trading world brought new information requirements. Trade routes – particularly as international trade expanded – were uncertain. Maps were imperfect. Transportation techniques were stretched to the limit. Communication lines were longer. Existing merchandise varied in quality. Novel goods were being discovered. Prices fluctuated wildly. Currencies differed across space and time. New methods of transferring and exchanging money were being invented.