Over the years the terms Stock Scanner and Stock Screener have become a bit blurred. On the surface they seem interchangable, but back when originally conceived they each were designed for their own purpose.
Scanners were built to stream stock data with filters to remove stocks outside of interest before being displayed. This helps traders by showing stocks moving based on their criteria and acts as a "dynamic watchlist" by presenting opportunities as quickly as possible.
Screeners on the surface may look similar, but are distinguished by usually having more complex settings and configurations. The idea with a screener is that traders want to manipulate the data via sorting, filtering or evaluating for deeper analysis or longer termed investment.
Obviously breakouts found in a scanner could be used for longer termed swings or holdings and similarly it is possible to use a screener for finding quick scalps. Its just the intent is a bit different.
Behind the scenes and perhaps the best way to define whether the functionality is that of a Scanner or a Screener is whether or not the data is persisted. Meaning is the data "saved" as part of calculations or for historical review. Screeners have days or months worth of data from which to provide trends, unusual volume, and other values. Scanners should stream data direct from the exchanges as quickly as possible (as in Realtime) and should not be exposed to too much backend processing.
And while many businesses offer "Screeners", Scanners are more rare. In fact, the few that we are aware of have been discontinued. TD Ameritrade had one, but removed it from their trading platform in 2019. We think this is due to the difficulity in managing the data stream in real-time. Our scanner functionality requires 20x more resources than our screener.
With the release of MOMO Pro we integrated both a Scanner and Screener into one common platform, but with a focus on momentum. We call our scanner our "Stream" and our screener, "Discovery". For the most part we respect the above definitions, with the possible exception that we cache the Stream for easier reference. We also include additional features to help traders watch and uncover new trades.
Interested in checking out MOMO Pro? Check out our available options. All plans come with our 5 day trial.