# Types of Operators

The following guide explains the different types of operators we offer, along with the knowledge necessary to successfully use them to create powerful conditions in your stock screens and trading models.

Operators tell the filter what to do with the data you select. You can think of Operators as the verbs in the filter.

## Across Operators

Across Operators allow you to calculate data fields or terms across any set of stocks. For instance, one could find the average (Total Assets / Total Liabilities) across stocks with a market cap greater than 50 billion. Or one could require that a stock’s PE must rank in the bottom 25% of its industry. The possibilities are endless.

In the across operators, there will be an **across** field and a **where** field, as shown below:

After the **across **field, you will indicate the set of stocks to be included. After the **where **field, you will indicate what requirements the set of stocks must meet to be included in your results.

Here is a list of our supported Across Operators:

## Within Operators

“Within” Operators have a field that allows you to specify the number of trading days to evaluate the operator. The operators perform many functions. For Instance, one could find stocks whose close is always greater than their open within 5 trading days. Or, one could compute moving averages using the average within the operator.

Here is a list of all supported Within Operators:

## Since Operators

“Since” Operators have a date field where you specify what date to evaluate the operator from. For instance, one could find stocks whose quarterly sales have always increased since 01/01/2009. Or one could find stocks whose current closing price ranks in the top 10% of all of its closing prices since 06/01/2012.

Here is a list of all supported Since Operators:

## Normal Operators

Besides our across, within, and since operators, we have other operators that perform a range of functions that allow you to create robust conditions.

Some more examples include: