Abstract: A computer implemented method and system for automatically setting prices of financial activities which culminate after a period of progressive development. The financial activities have a plurality of possible outcomes and include weather-related or other naturally occurring events as well as sporting events and sporting competitions. The method includes receiving a first request from a participant terminal to purchase a financial product for one of the possible outcomes, i; and electronically computing a price for the requested financial product, in response to the first request, based at least in part on a first formula. In one example, the financial products include contracts in a one-sided market of buyer participants where the outcomes are mutually exclusive and collectively exhaustive.