Before the development of ETOS software there were no solutions that supported the brokers of the electric energy market in the optimization of their energy product purchases. Our Energy market Optimization Software was developed to assist the brokers in making continuous and up-to-date product portfolio optimizations based on the latest prognosis so that as a result they could determine the cheapest correction portfolio adjusted to the changed circumstances. Our software results in significant savings to brokers who are able to achieve lower specific energy prices with the continuously optimized portfolio selection. The software was tested with the involvement of the main players of the domestic electric energy market. In this way EPOS has become an efficient application adjusted to the market’s conditions and demands.