TinTO is an experimental system aiming at demonstrating the usefulness and feasibility of applying conventional SQL queries for analyzing a wide spectrum of data streams. As application area we have chosen the analysis of streams of stock market data, mainly because this kind of application exhibits sufficiently many of those characteristics for which relational query technology can be reasonably considered in a stream context. TinTO is a technical investor tool for computing so-called technical indicators, numerical values calculated from a certain kind of stock market data, characterizing the development of stock prices over a given time period. In contrast to other approaches, TinTO computes indicator values directly over the database by means of SQL queries/views.