Commodity price data methodology.

Daily oil prices

WTI and Brent daily observations come from EIA spot-price series distributed by FRED (DCOILWTICO and DCOILBRENTEU). They use USD per barrel and may be published in delayed batches. A daily scheduled check preserves source dates, gaps and valid negative oil values. These daily series are distinct from futures settlements. A reference more than fourteen days old is labelled stale; the observation date remains visible before that threshold. Monthly WTI, Brent and Dubai retain World Bank averages; yearly prices average monthly values. Oil comparisons use only shared dates, and spreads subtract the second benchmark from the first. Oman, Murban, WCS and the OPEC basket use dedicated benchmark profiles with clearly defined price, supply and methodology coverage.

Sources: WTI daily spot history and Brent daily spot history.

Hourly precious-metal references

price-chart.com checks Gold API once each hour for timestamped USD-per-troy-ounce spot references for gold, silver, platinum and palladium. Its terms permit commercial website use of the keyless price endpoint. Each observation is validated for the requested symbol, USD currency, source timestamp, freshness and a finite positive price before publication. Hourly observations are stored separately from daily history and never converted into invented daily closes. If the hourly source misses its freshness window, the price card falls back to the latest available daily or monthly series while keeping the period and delay visible.

A separately licensed Twelve Data feed can extend hourly coverage to WTI and Brent. Industrial-metal intraday display requires exchange distribution rights and a feed matching the grade, location and published unit. Until those rights are configured, copper, aluminium, nickel, zinc, lead and tin retain their clearly labelled monthly references.

Daily reference prices

price-chart.com publishes daily USD-per-troy-ounce reference observations for gold, silver, platinum and palladium from a CC0 reference archive. These are aggregated currency-conversion references, not exchange closing prices or executable spot quotes. We invert the published XAU, XAG, XPT and XPD rates, validate their dates and check hourly for a new daily publication. Missing archive dates remain gaps. References older than four days are labelled stale.

Monthly historical references

World Bank Commodity Price Data (the Pink Sheet) supplies nominal USD monthly averages. Month labels refer to the observation period, not a transaction on the first day of that month. The original series is retained in its published unit. Missing values are omitted, never replaced with zero or fabricated prices.

Source: World Bank commodity markets. Dataset: Commodity Prices: History and Projections, CC BY 4.0. price-chart.com converts units and currencies and charts the observations. No endorsement is implied.

Spot quotes

The hourly precious-metal service preserves the provider timestamp, and market closures or source interruptions can affect availability. The visible delay is calculated from the stored observation time rather than the page-load time. A separate faster spot service remains disabled unless both provider credentials and public-redistribution rights are configured.

Changes and chart frequency

Monthly change compares the latest monthly average with the preceding stored month. A spot quote change compares the previous stored spot observation; it is not labelled a daily change. Daily, monthly and yearly chart controls select separate series. Yearly values average the available monthly observations. Partial years and incomplete daily-derived months are labelled, and their percentage changes are withheld. Palladium monthly means are calculated from stored daily snapshots; other monthly series retain World Bank data.

Currency and weights

Frankfurter supplies reference exchange rates. We check every twelve hours for three calendar months after launch, then hourly. The source may update only daily. Historical currency views use the latest reference FX rate across all dates, not historical FX returns. One troy ounce is 31.1034768 grams. Base metals default to metric tonnes; oil uses barrels and US gas uses MMBtu. No mass conversion is offered for energy.

Coverage and limitations

Launch coverage includes gold, silver, platinum, copper, aluminium, nickel, zinc, lead, tin, Brent, WTI and US natural gas. Palladium has daily reference history. Other traded materials, including rhodium, cobalt, lithium and steel products, need a defined specification and suitable data rights before a price page can be added. These references exclude retail premiums, transaction costs and taxes.