Users who are interested in keeping up with the stock market find applications for stock alerts very useful. Current applications focus on delivering instantaneous alerts, i.e. the alert at a given time is greater/lesser than X. However, instantaneous alerts do not inform users about consistencies in the stock prices. As a result, more complex types of alerts, like averages over various time windows can prove to be invaluable. However, supporting such complex subscriptions along with large volumes of data becomes a challenging task. This motivated our design for Stockr. We developed a scalable streaming event processing system that can support more advanced subscriptions. The core novelty of our application is the underlying system. This scalable distributed monitoring framework can prove to be valuable in a variety of scenarios such as monitoring of system logs. We are excited about continuing to expand on our work as we see an applicability in various domains.