Charting and Studies User Guide - CQG.com

To use logarithmic or linear scale
This scale applies to daily or historical charts only.
1. Right-click the price scale.
2. Point to Scale Type.
3. Click Log or Linear.
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Log is a mathematical treatment; a change in the logarithm of a variable is approximately its
percentage change. The Y-axis of a linear chart arranges prices equidistantly. A change of $2 is
indicated in equal increments every time there’s a $2 change. With a log chart, that equal price
distribution is no longer the case. Instead, the Y-axis of a log chart distributes prices according
to percentage change. A $2 change may be 10% at one time and only 1% another time. Log
charts expose that relationship.
Log charts are an effective way to look at the history of a symbol. It might also be a beneficial
way to look at contracts with a lot of price movement.
Notice in this image that a logarithmic view provides a clearer picture to compare the DJI c.
1929-1930 with now:
Charting and Studies User Guide