Plotting a plunge
April 3, 2025 at 1:38 PM by Dr. Drang
Earlier today, I opened the Stocks app to see how bad things were after yesterday afternoon’s tariff announcement. I thought its one-day plots weren’t very useful. Here’s APPL:
Strictly speaking, this is correct, as the share price started way down from yesterday’s close. And I guess Apple is trying to give us a sense of this by setting the top end of the plot’s range up where the price was yesterday. But anyone looking at today’s action would want to see yesterday’s closing price explicitly.
Google Finance does a better job:
The dashed horizontal line shows you where things were yesterday, and the closing price is also given as that line’s label. Much better.
Maybe if Tim Cook gave $1 million to the team making the Stocks app, they’d make better plots.
Update 3 Apr 2025 2:39 PM
Connor Graham points out that the dashed line at the top of the Stocks plot is yesterday’s close. I saw that line but thought it was associated with the 224 axis label off to the right. Nope. There’s actually a thin gray line above the dashed line, and that’s the 224 level. Here’s a zoomed-in view (something not available in the app itself):
What’s funny is that I could see the other horizontal grid lines, just not the one that’s close to the brighter dashed line. I bet people who study perception have a cool explanation for that.
So I should revise my criticism of the Stocks plot:
- It’s grid lines are too faint to distinguish the top one from the dashed line.
- Because it uses stupid choices for the grid locations (224? not 225?), the dashed line is always close to the top grid line.
- Because it puts the grid labels too far below their associated grid lines, the top label looks like it applies to the dashed line.
- It doesn’t label the dashed line. This is a minor criticism. If I’d been able to see that the dashed line was distinct from the top grid line, I would’ve known that the dashed line was yesterday’s close.
So Tim doesn’t have to spend the whole $1 million on Stocks.
Thanks, Connor!