Pre-Scan conditions operate different from normal conditions used in a standard EasyScan, Sort Column, Alert or Report. Here is some helpful information.

Definition: A pre-scan condition is used to always filter the combined WatchLists of a combo list. Just as the combo list automatically combines the current components of multiple WatchLists each time you open it, the pre-scan conditions filter those combined results by those conditions. Because of how they operate, pre-scan conditions function best when they are broad filters (e.g. a price range, volume minimum, market cap, etc.) as opposed to very specific conditions normally used in an EasyScan (e.g. a moving average crossover or indicator trigger). Pre-scan conditions should be filters that do not change or rarely change on an intraday basis. They are also conditions you  always want to be true of any of the symbols in your list. The purpose of pre-scanning is just to qualify your list with items that meet your basic liquidity and price needs to be tradeable by you. Examples are provided below in this article.

Functionality: Pre-scan conditions are applied to the combined WatchLists (Combo List) each time that list is opened in the software. Every hour after that the pre-scan conditions are reapplied to the Combo List. Unlike EasyScan conditions, there is no way to manually force a refresh of these conditions short of closing and re-opening the list.  

Note: More specific scan conditions to filter any Combo List can be used to identify more complex or dynamic behaviors when you apply them in a normal EasyScan. This allows you the ability to manually refresh conditions or set an automatic refresh rate. (Pre-scan conditions are not best used for this purpose.)

Click the WatchList menu button and choose New Combo List or click the asterisk button next to the Combo List tab.

Alternately, click the New button and select New Combo List from the drop down menu

This opens the WatchList library containing all System and Personal WatchLists. Use the Search (typing shortcut) field to locate the desired WatchList. (Alternately, select a category of WatchLists and scroll through the list to select.)

Add multiple WatchLists from the library to get the desired combination.

This opens the Condition wizard

Type to search for criteria to create the condition(s)

Use the condition, value, true and timeframe drop down menus to create the desired condition. Click OK to save the condition. Repeat the process for multiple conditions.

1. Here is an example of combined WatchLists (1) and Conditions (2)

The example here is a condition filtering for stocks whose current price per share is higher than $5, 90-day average volume is greater than 250,000 shares and the stocks are optionable. Any number of conditions can be added here. (Click Here for more on adding conditions.) Pre-Scan conditions should be thought of as broader conditions you might want to see on most stocks you look at. They are updated once per hour.