DSA: Daily Stock Activity

I was trying to identify stocks whose daily price movements were dramatic. Stocks that opened, then rose and/or fell ...

>Dramatically?
Exactly! So I thought I'd measure this daily stock activity by calculating (High - Low)/Open, expressed as a percentage.
If it was 2.0%, it meant the spread between High and Low was 2.0% of the Opening price ... and that'd be significant.

>What's it called, this measurement of daily stock activity: (High - Low)/Open ratio?
I dunno. What do you suggest?

Excellent!
 Daily Stock Activity (DSA) = (High - Low) / Open
Anyway, I looked at various stocks and ...

>Don't tell me! You have a spreadsheet.
Of course.
It looks like this:

• You type in Yahoo symbols for 30 stocks (in Column K).
• You click a button (called "get Stock DSAs").
• A years worth of daily stock prices is downloaded and the DSA is calculated each day for each stock ... and plotted.
• The list of stocks is sorted according to their average DSA ... and plotted.
• When the downloading is completed, you can move the slider to stare in awe and wonder at each of the 30 stocks.
In the picture of the spreadsheet, it's stock #26: the DOW, with an average DSA of 2.0%