Scans allow you to quickly find all of the stocks, mutual funds, and indices in our database that meet whatever technical conditions (also called "scan criteria") that you select. For instance, you can scan all the stocks traded on the New York Stock Exchange and find only those that have reached their 52-week highs.
The program that evaluates your scan conditions and generates your scan results is called the Scan Engine. To specify the scan criteria for your scan, you can use one of two different scan workbenches (also called "scan interfaces") - the Standard Scan Workbench and the Advanced Scan Workbench. The Standard Scan Workbench makes it very easy to create, store and run scans with just a couple of clicks. The Advanced Scan Workbench allows expert users to create complex scans with compound criteria. We recommend that everyone start by using the Standard Scan Workbench and only convert over to the Advanced Scan Workbench if it is really needed. The rest of this document describes our Standard Scan Workbench.
By the way, if you are just learning to create scans, we recommend that you download and print our Scan Tutorial and then slowly follow its directions. Scanning is incredibly useful but it does take time to learn. Our Understanding Stock Scans article may also be useful. Finally, you might also want to review the information and example scans in our Scanning Stocks blog.
If you are serious about scanning, you'll need to subscribe to our "Extra", "ExtraRT" or "PRO" service. Extra and PRO members can create and store scans inside their account, see up to 1,000 results from their scans (the maximum we allow), and use our Advanced Scan Interface.
Free users and Basic subscribers have access to our Predefined Scan Results - a collection of scans that we run everyday after the market closes. A list of our Predefined Scans and their definitions can be found here.
There are two ways that Extra and PRO members can access the Standard Scan Workbench:
From the Members page, click on the Standard Scan Workbench link in the control center.
When the Standard Scan Workbench page appears, it should look similar to this:
To begin creating scans, make sure you are logged in and click on the Stock Scans link on the left side of the page.
Click on Create your own scans in the top right of the page to go to the scan workbench. The first time you see it, you will likely be a bit confused by the many options available, but trust me, they are quite easy to learn and you will be glad they are all there!
From this page, there are three steps to creating your scan:
Use the dropdown controls on the page to specify the criteria that you wish to scan for.
Press the Update Criteria button to add your changes to the light-blue Criteria box in the middle of the screen.
When the Criteria box contains the scan you want, click the Run Scan button to see the results.
A stock scan applies a technical formula to a large population of stocks and returns a list of stocks that meet some filter criteria associated with that formula.
By technical formula, we mean a calculation that uses a stock's price data (open, high, low, close) and/or volume data over a given period of time to compute some value. By large population, we mean an easily defined collection of stocks that is too large to screen by hand. By filter criteria, we mean the range of valid values for the results of the calculation.
Now let's look at the description of a very simple stock scan:
All NYSE stocks whose current 50-day simple moving average is anywhere above their current closing price.
In this example, the technical formula is the 50-day simple moving average formula, the large population is the set of all stocks traded on the New York Stock Exchange (NYSE), and the filter criteria is any value above the given stock's current closing price. The criteria box for this scan would look like this:
To create this simple scan, we selected "NYSE" as the Group and added one Additional Technical Expression.
There are three major areas in the Standard Scan Workbench - the Global Filters, the Predefined Chart Patterns, and the Additional Technical Criteria. The following sections explain how to use each of these areas.
Global Filters are where you specify the "large population" of stocks that you wish to search thru. Here's what the Global Filters area looks like:
We recommend that you always specify at least one Global Filter in your scan. Our system is optimized to run scans with Global Filters faster than scans without them. Here are the descriptions for each of the lines in the Global Filters area:
From the Group dropdown, you can indicate that your scan only applies to symbols from a given country, from a given stock exchange, from a given major index, or from one of your saved ChartLists.
Tip: If you have all of your favorite stocks in one ChartList, use the Group dropdown to select that list so you can run scans against those symbols looking for buy or sell conditions.
From the SCTRs dropdown you can select a range of SCTR values for various SCTR groupings.
You can specify minimum average volume levels over the past n days. For example, you can set the scan to find stocks whose average volume over the past 60 days is greater than 100,000.
Tip: Always include an Avg Vol setting in your scan. It will make the scans run much quicker. In addition, technical indicators often give misleading signals on very low volume stocks.
Note: To specify a maximum average volume setting for your scan, use the Additional Technical Indicators area (see below).
You can also specify the minimum average price level over the past n days. For example, you can set the scan to find stocks whose average price over the past 60 days is greater than $50.00.
Note: To specify a maximum average price setting for your scan, use the Additional Technical Indicators area (see below).
In addition to your other custom filters, you can apply your scan to the results of one of our many Predefined scans. For example, you could scan for all stocks that reached a new 52-week high and also traded over $2.00.
Note: To modify one of our predefined scans, use the Select Scan to Insert dropdown below the Additional Technical Criteria area.
The Scan Engine can recognize a large number of predefined Candlestick and Point & Figure chart patterns. You can add criteria for up to four of those patterns to your scan using the dropdowns in the Predefined Chart Patterns area. Your criteria can look for a chart pattern to be "true" or "false". A "true" pattern means that, on the daily version of the chart, the final couple of candles or P&F columns form the pattern specified. A "false" pattern means that the daily version of the chart does not have the specified question on its right edge.
Tip: Some patterns can be true for several days, weeks or even months. To find stocks which have just completed the pattern today, use two criteria - one where the pattern "zero days ago is true" and one where the pattern "one day ago is false".
This is where the "meat" of most scans is specified. An Additional Technical Expression is a mathematical expression consisting of a technical indicator, and operator, a second technical indicator and an optional multiplier. Either of the technical indicators can also have an optional date offset.
The Additional Technical Expressions area allow you to add up to four different technical expressions to your scan. When you click the "Update Criteria" button, all of the lines are "Add'ed" together to create your final scan criteria.
In Indicators dropdown contains both data fields (i.e., Open, High, Low, Close, and Volume) as well as technical indicators (MACD, RSI, Stochastics, etc.).
Use the Parameters fields to specify whatever parameters your selected indicator requires.
Use the Date Offset field to specify the number of periods (days or weeks) into the past that the indicator should be moved. Remember this is trading days.
Use the Period dropdown to specify if the indicator should be evaluated on a Daily or Weekly basis and to specify if the offset refers to days or weeks in the past.
Use the Comparison Operator dropdown to specify the type of comparison you wish to make between the two sides of the technical expression.
Use the Multiplier field to scale the results on the indicator on the right side of your expression.
Think of each entry field as a piece of a sentence that you are dictating to the scan engine. The criteria box at the top of the page does this for you after you hit the button. Let's see a few examples:
"Search for stocks with a daily close today that is at least 50% greater than the daily close yesterday"
"Search for stocks with a daily volume today that is over 3x greater than the 260-day simple moving average of volume AND
for stocks with a daily close today that is more than 50% greater than its 30-day simple moving close average"
"Search for stocks with a MACD line (12,26,9) that crossed above the MACD signal line (12,26,9) today AND
for stocks with a daily volume today that is over 3 times greater than the 50-day simple moving average of volume"
"Search for stocks with a closing price greater than 150"
Our Scan Engine is essentially a big computer with up to 800 days of Open, High, Low, Close and Volume information for every symbol in our database in its memory. That is a *ton* of data and keeping it up-to-date is a full time job. There are two limitations that you need to keep in mind when constructing your scans:
Long-term indicators, especially those based in some way on Exponential Moving Averages that are longer than 200 days, will lose some accuracy.
Indicators based on long-term date offsets may also lose some accuracy.
Note: Our SharpCharts charting engine has access to much more data than our Scan Engine does and provides a more accurate technical picture for long-term charts.
To learn more on writing scans check out our Part 1, Part 2 and Part 3 videos.