Methodology.
Every number on World Markets can be traced to a source you can check yourself. This page says exactly where each of the 220 indices comes from, how a raw quote becomes the unit we print, and what happens when a source stops answering.
01Where each price comes from
Indices are grouped by the kind of source behind them, not by what they are. A barrel of crude and a bushel of corn share a source; a sealed Pokémon box and a knife skin do not.
| GROUP | COUNT | SOURCE | POLL | QUALITY |
|---|---|---|---|---|
| Metals, Energy, Agriculture, Livestock | 29 | Front-month futures quote from the Yahoo Finance chart endpoint (GC=F, CL=F, ZW=F and so on), converted from US cents where the contract quotes in cents. | 5 min | LIVE |
| Currencies | 126 | USD reference rate from the exchangerate-api open endpoint, inverted to USD per unit and multiplied by the catalogue lot. The upstream publishes once a day. | 10 min | LIVE |
| Trading cards | 25 | TCGplayer market price of the exact print, read from the tcgcsv daily mirror. Product ids are resolved once and pinned, so a reprint cannot silently swap the index. | 6 h | DAILY |
| CS2 skins | 12 | Steam Community Market median price for the exact item and wear. Steam rate-limits hard, so misses are expected and the previous value is kept. | 3 h | DAILY |
| Fast food, Drugs, Cars | 26 | Published US list price, or for the drug indices a documented street-price estimate drawn from public DEA and UNODC reporting. These change when the menu, the manufacturer or the published estimate changes, and not otherwise. | — | LIST PRICE |
| Water, Game gold | 2 | Documented reference level. The Nasdaq Veles California Water Index and the OSRS gold market both lack a free programmatic feed, so these sit at a stated level until one exists. | — | REFERENCE |
The per-index source string is served by /api/commodities and shown in the commodities table, so you never have to guess which group an index belongs to.
02Units and lots
Futures do not quote in the unit a person thinks in. Grains, softs and livestock quote in US cents, so they are divided by 100 to reach dollars per bushel or per pound. Everything else is passed through untouched.
ZW ZC ZS ZO cents/bushel → USD/bu
ZL SB KC CT OJ cents/pound → USD/lb
LE GF HE cents/pound → USD/lb
# everything else is already in the printed unit
GC SI PL PA USD/oz CL BZ USD/bbl CC ALI USD/tonne ZR DC USD/cwt
Weak currencies are printed in round lots so the number stays readable: one index is 1,000 VND, another is 100 NGN. The lot is part of the unit string and is applied to the rate, never hidden.
03Staleness
Every index carries a limit sized to its source. Past that limit it is marked STALE on the site and in the API, in the same object as the price, so nothing downstream has to infer it.
futures 72 h (closed sessions and weekends)
currencies 36 h (upstream publishes daily)
cards, skins 96 h
list price none (a menu price does not go stale)
04What World Markets does not do
- No interpolation. There is no mean-reverting filler between refreshes. A flat line means the market was flat, not that the feed died.
- No anchored proxies. An index is the source number in the printed unit. Nothing is scaled to a made-up dollar level to look more interesting.
- No hand-edited marks. The only levels set by hand are the 28 explicitly labelled LIST PRICE and REFERENCE indices, and they are labelled everywhere they appear.
05History
Observations are folded into OHLC buckets at 1m, 5m, 15m, 1h and 1d as they arrive. Gaps stay gaps: if a feed was down for an hour there is no candle for that hour, and the chart shows the hole instead of drawing a straight line across it. The 24h column compares the current price to the hourly close nearest 24 hours ago, and reads 0.00% until there is a day of history to compare against.
06Scope
World Markets publishes price indices. An index is not a claim on the underlying: holding an index level for gold is not holding gold, and the drug indices are a published estimate of a street price, not an offer of anything. Where a name is a trademark it belongs to its owner and is used to say what is being priced.