PerfChart of a logarithm of a stock symbol?

SimpleInvestor

On a PerfChart, is there a way to plot the logarithm of a stock symbol?

I tried log(VTI), ln(VTI), log10(VTI), etc., but none of those work.

If this is not currently a feature, then how would I go about requesting this from the developers?

A logarithmic view can be especially helpful for visualizing long investment time series where the exponential growth becomes more obvious, and the absolute price swings at the start of the record represent much larger fractional changes than at the end of the record.

A log() capability would also be very useful when plotting multiple symbols. For example, comparing log(VTI) to log(VXF) would display a log-plot of their relative performance ratio, since the "difference of logs" equals the "log of the ratio". This could effectively generate a classic Bogle-type "telltale chart," which compares the ratio of cumulative performance between two investments. This is much easier to interpret than the current PerfChart "relative performance" comparisons, which (when one clicks on a symbol) actually simply subtract that symbol from the others. This can easily lead one to misinterpret trends in relative performance, e.g. https://scan.stockcharts.com/discussion/comment/6297#Comment_6297.

markd

You can send a request to support. I have found they are responsive to well thought-out, constructive criticisms/suggestions, which this certainly is. However, the request likely goes onto a list of projects and then needs to get a priority for a future build, so it will likely be a wait if they agree to do it.

It would probably help to write something detailed that can serve as a complete high-level specification, so the developers get a good idea how to proceed (e.g. how many symbols, how long a look back, etc.). What you have is a great start.

On your home page, click on Help in the upper right corner, then in the blue box under the "Support Center" heading, click on the link on the third line "To send us a question or concern".

lmkwin

PerfCharts are basic ROC for each symbol for the slider period. You can use Unadjusted Data on them by putting an Underscore in front of the symbol. Over longer periods this might provide a different view. The most recent enhancement there was creating a bunch of Predefined groupings that you can use. And I think the CandleGlance Group is a new option as well.

On the price chart, obviously you can select Log scale on the main chart. In the Overlays you can select Price and Price Performance with a symbol. Ratio symbols work here as well as the main chart.

On the Price Overlay it defaults to algorithmic scaling. You can change to logarithmic scaling by using Symbol comma log in the parameter field. AAPL,log

This appears to work with ratio symbols AAPL:$SPX,log and it doesn't appear to work in the Price Performance Overlay.