Intro to Prisms
Prisms is a free, public page of reference charts computed daily by Carbon Arc from Carbon Arc data assets. Each chart tracks two measures for a defined group of named brands through the current month:
- Growth — how a brand is growing versus the same period last year
- Share — how brands in the group stack up against each other
No account is needed. This guide explains what the charts show and how to read the numbers.
A number is either a growth index (compared with the same period last year) or a share of a stated group. A Prism will never include dollar amounts, visit counts, download counts, or any other absolute total.
For the rest of this guide, imagine a prism called "Coffee chains" in the Credit Card Spend category, containing Starbucks, Dunkin', and Dutch Bros, US region. All example numbers below — every index reading and share split — are invented for illustration. They are not real Prisms readings.
How the Page Is Organized
Tiles are grouped into category shelves that tell you what kind of activity the charts measure.
| Element | What it does |
|---|---|
| Category shelf | Groups tiles by the kind of activity measured, e.g. Credit Card Spend or App Downloads |
| Tile | One brand, one measure. A brand may have a Growth tile, a Share tile, or both |
| Ordering | Growth tiles first, then Share tiles, with brands ordered by current growth — fastest first |
Three controls narrow the page:
- Find a prism — search box
- Category pills — filter to one category shelf
- Metric — filter to Growth or Share
Click any tile to open the full chart. From there you can:
| Control | What it does |
|---|---|
| Timeframe | Switch between This month (month-to-date) and Historical (the past 12 months) |
| Series | Compare the brand against the others in its group, or view it Solo |
| Metric | Flip between Growth and Share |
| Legend | Select any other brand in the group to make it the focus |
The address bar updates as you go, so you can copy the link to share exactly what you're looking at.
Reading a Growth Tile
The growth index answers: how is this brand doing compared to the same time last year?
100 means exactly the same as last year, through the latest available day of data.
| Reading | What it means |
|---|---|
| 112 | Running 12% ahead of last year |
| 100 | Flat |
| 93 | Running 7% behind last year |
| — | No prior-year data to compare against — we show nothing rather than an estimate |
The default view is month-to-date: everything from the 1st of the month through the latest day of data, compared against the same calendar days one year earlier. If a coffee chain's tile reads 112.4 on July 15, its measured activity for July 1–15 is about 12% higher than it was over July 1–15 last year.
Think of the index as pacing
The month-to-date index is where the month is pacing to land, given the days measured so far.
- On July 1 the index compares a single day against the same day last year, so a reading of 110 means the month is pacing to finish 10% up.
- If July 2 comes in much weaker, the two days combined might read 102 — now pacing 2% up.
- Each new day feeds the running total and prior days stay counted, so a single day moves the number less and less as the month fills in.
Expect the line to wiggle early and settle late. It keeps changing until the month closes.
A few things to keep in mind
- The Historical view shows one point per month: that month's total versus the same month a year earlier.
- The comparison uses the same calendar days, not the same weekdays. Early-month readings can shift slightly when this year's date range contains an extra weekend.
Reading a Share Tile
Share answers: of the brands on this chart, what's this brand's slice?
It is each brand's portion of the group's combined total, so the shares on one chart always add up to 100%. If a three-chain coffee chart shows 57.6%, 32.4%, and 10.0%, that is how the measured activity splits among those three chains.
The group is exactly the brands named on the chart — not the whole industry. A brand with 58% here does not hold 58% of the coffee market; it holds 58% of activity among the chains shown.
Growth and Share Tell Different Stories
This is why many brands appear with both a Growth tile and a Share tile.
| Growth | Share | |
|---|---|---|
| Question answered | How is this brand doing versus last year? | What's this brand's slice of the group? |
| Compared against | The same calendar days one year earlier | The other brands on the chart |
| Baseline | 100 = flat | The chart's brands sum to 100% |
The smallest brand in a group can be the fastest-growing one — a small slice getting bigger quickly.
How Fresh the Numbers Are
Charts are recomputed and published on a fixed daily schedule. Every tile carries its own freshness line:
UPDATED DAILY · LAST REFRESHED [time] · DATA THROUGH [date] · REPORTING LAG ~[N] DAYS
- Data through is the most recent day of underlying data. Panel data takes time to arrive, so this usually sits a couple of days behind today.
- Month-to-date figures keep updating until the month closes, which might be after the end of the calendar month. This depends on the individual dataset.
- The Historical view shows complete months only, so a month that is still filling in will not appear.
- As further described in the Prisms Terms of Use (linked from the page), underlying panel data can be revised. Each refresh recomputes the chart from the latest available history, so a restated past value updates the chart's earlier points too — not just the newest day.
Prisms at a Glance
| Prisms is | Prisms isn't |
|---|---|
| Relative reference numbers: growth vs last year, and share of a stated group | Dollar amounts, visit counts, or any absolute totals |
| Updated daily from Carbon Arc's data panels | Real-time — data arrives with a natural delay |
| Share of the brands shown on the chart | Market share of a whole industry |
| Panel-based estimates that may be revised | Company-reported or official figures |
| Direct calendar-day comparisons | Weekday-aligned or seasonally adjusted statistics |
| Free and public — no account needed | A data feed or download service |
Prisms FAQs
1. Do I need a Carbon Arc account to use Prisms?
No. Prisms is free and public. Open app.carbonarc.co/prisms and start reading.
2. What does a growth index of 112 mean?
It means the brand is running about 12% ahead of the same calendar days one year earlier. 100 is flat, and anything below 100 is running behind last year.
3. Why did today's reading move so much from yesterday's?
Early in the month the index is built from only a few days, so each new day carries a lot of weight. As days accumulate, prior days stay counted and a single day moves the number less and less. Expect early wiggle and late settling.
4. Is Share the brand's market share?
No. Share is the brand's portion of the combined total for only the brands named on that chart. It says nothing about the brand's position in the wider industry.
5. Why does a tile show a dash (—)?
There is no prior-year data to compare against for that period. We show nothing rather than publish an estimate.
6. Why is "data through" a few days behind today?
Panel data takes time to arrive. The charts are recomputed daily, but the most recent day of underlying data typically sits a couple of days behind the current date. Each tile states its own reporting lag.
7. Can past values change?
Yes. Underlying panel data can be revised, and each refresh recomputes the chart from the latest available history. A restated past value updates the chart's earlier points, not just the newest day. See the Prisms Terms of Use for details.
8. Why doesn't the current month appear in the Historical view?
The Historical view shows complete months only. The month in progress lives in the This month view until it closes.
9. Can I download the underlying data?
Not from Prisms — it is a reference page, not a data feed. To work with the underlying data, build a framework in Builder.
10. Can I share a specific chart?
Yes. The address bar updates as you search, filter, and open tiles, so copying the link shares exactly the view you are looking at.
Need help? Contact us at support@carbonarc.co