Request to Stockopedia to display share price graphs so that their price axes start at zero.

29th Jan '18 by pka

9 comments 4900 reads

Would any people, other than myself, like Stockopedia to change their share price graphs so that their price axes would always start at zero, or at least to have an option to display graphs in that way?

At present, the graphs have their price axes starting and finishing at the lowest and highest price, respectively, over the time-period of the graph. But that means a 20% increase for one stock over the selected time-period looks visually the same as a 200% one for another stock, which is very deceptive unless one is careful to read the numbers on the axes.

Truncating the y-axis, which is what the present graphs do, is one of the techniques recommended to fool people in this classic book:

https://en.wikipedia.org/wiki/How_to_Lie_with_Statistics

In our case, we're just fooling ourselves, but that's a very easy thing to do!

Unlock with Email

Unlock with Google

Already have an account?
Login here

Redrichmond

29th Jan '18

Try posting it in here..

http://ideas.stockopedia.com/forums/18977-stockopedia-pro-feedback

pka

Redrichmond,

Thanks for the suggestion. I will try to do that.

JohnEustace

I don't know a way to make it the default but you can adjust the axis manually.
On the PC in the chart view, move your cursor to the axis on the right. The cursor arrow changes to an = sign with arrows above and below. Click and hold the left mouse button down and drag up or down to adjust the scale.

You can also choose log scale or percentage scale from the settings button and save that setting as a template. If you want to compare two or more instruments on the same chart it defaults to log scale.

John, Thanks for your suggestion, which is fine if you're just looking at one or two graphs.

However, if you have a Stockopedia folio, and click on the little button on the top right of the screen to display graphs of all your holdings, you will have too many graphs for your suggestion to be practical.

Nick Ray

30th Jan '18

Unfortunately graphs starting at zero don't really help.

Firstly for a stock which is priced at (say) 2200 you will hardly be able to see any movement at all.

Secondly, it does not even help with comparison because a stock whose price goes from 100 to 120 is a rise of 20 and so is a stock which goes from 500 to 520 but in the first case we have a+20% gain and in the second case the gain is only 4%.

The best way to compare stock returns is to use log graphs, but even thn unless you superimpose the stocks on the same graph it is difficult to make a meaningful comparison by eye.

A "trick" that I have used in graphs that I produce for myself is to add a "reference curve" in light grey to every stock chart, which gains (for example) 25% in a year and which starts at the same price as the stock being charted. The idea is that you will notice the steepness of the reference curve as you look at the graph which cues you in to whether this is a significant or minor price move.

Howard Adams

Hi John

Thanks for that tip I did not know about that functionality. That's useful.

Regards
Howard

Correcting myself, I should have said that if comparing two or more instruments the default is a % scale not a log scale.

Nick, You wrote:

"Unfortunately graphs starting at zero don't really help.
Firstly for a stock which is priced at (say) 2200 you will hardly be able to see any movement at all."

I disagree - surely a higher priced stock is ikely to have similar percentage movements as a lower priced one, if they have similar volatilities.

"Secondly, it does not even help with comparison because a stock whose price goes from 100 to 120 is a rise of 20 and so is a stock which goes from 500 to 520 but in the first case we have a+20% gain and in the second case the gain is only 4%."

Again I disagree - if a stock's gain is only 4%, I would prefer to see an almost horizontal graph for it, rather than seeing a very misleading graph showing it going up at the same angle as a stock that gains 20%.

Well you may be right. It can certainly highlight that we tend to fuss too much when a stock price moves by 10%. It looks a lot less frightening in its true context.

Here's what it can look like for a couple for randomly chosen stocks.

Request to Stockopedia to display share price graphs so that their price axes start at zero.

Unlock the rest of this article with a 14 day trial

About the Author

Pka

9 comments

Unlock the metrics for all these stocks and more...

Unlock the metrics for all these stocks and more...