All tracked markets
| From | To | Pairs | Unchanged | Up | Down | Left out | Step | Check |
|---|
Every price move in this view, in percent
By market
Markets are listed when at least one step has five or more same-project pairs. Click a market to see its chain.
| Market | Base date | Index now | Pairs | Moves up / down | Left out |
|---|
Official registered sales, for context
Where a government publishes its sales register openly, we show the monthly median next to the index. It is a different measure: it covers every unit sold, and the mix of units changes from month to month. It is never blended into the index.
How it is computed
- Observation. A project counts on a given day only if our research agent re-read its page that day and found a positive advertised "from" price with a currency. A value carried over from an earlier day is not an observation.
- Pair. The same project, observed on two consecutive snapshots, in the same currency. Projects that changed currency between the two are left out and counted.
- Jumps left out. A step of more than 25 percent up or down is left out and counted. In our data such jumps are nearly always a different unit type, a currency mix-up or a misread page, not a price change. We do not correct them.
- Step. The geometric mean of new price divided by old price over the kept pairs (a chained Jevons index). Unchanged prices count as no change. A step needs at least 5 pairs.
- Chain. The index starts at 100 on the market's base date and multiplies the steps since then. If a step is too thin, the chain is not bridged across it: the base moves to after the gap.
Limits: an advertised "from" price is the cheapest unit on offer, so it moves when that unit sells out as well as when a developer reprices. Prices are read from web pages by a language model and can be misread. Snapshots are not evenly spaced. Per-project amounts and names are not published, only percentage changes and counts, so projects stay anonymous.
Data: /data/price-index.json (CC BY 4.0), rebuilt every day after the research agent's run. Inputs and their SHA-256: …. Related: advertised prices versus registered sales, the database.