Data Sources & Methodology
So users know exactly where our prices come from, how often they update and what their limits are, this page sets out our data sources and methodology in full. We believe honestly labelling sources and uncertainty matters more than pretending to show a "live official price." That's why every gold, silver and crypto price on the site is labelled a reference value / estimate and shows its last successful update time.
1. Where each type of data comes from
- International spot gold/silver: from a public market data provider (gold-api.com), quoted in USD per ounce.
- Exchange rates (USD/HKD, etc.): from public FX sources (frankfurter.dev and open.er-api.com).
- Cryptocurrency prices: from a public crypto market source (CoinGecko, with CoinPaprika as a fallback).
- Historical charts: embedded charts provided by TradingView.
- Jeweller / bank information: a directory of names, categories and official-site links only — not any shop's official quote.
2. How data is fetched and cached
All market data is fetched from the above third parties via a same-origin Cloudflare Worker and briefly cached server-side. This reduces the impact of upstream API outages or latency, avoids exposing third-party endpoints in the browser, and lets us attach a consistent "last successful update time." When an upstream source is temporarily unreachable, the system shows the last successful data with a timestamp or a clear error message — it never passes off unverified numbers as a live price.
3. The HKD gold conversion formula
Our core HKD gold conversion is:
(spot gold USD ÷ 31.1035 × 37.429) × USD/HKD rate = HKD reference price per tael
Here 31.1035 g is one troy ounce and 37.429 g is one Hong Kong troy tael. The per-gram price is the per-tael price ÷ 37.429. Different fineness levels (999.9, 999, 916/22K, 750/18K, 585/14K, 375/9K) are converted by purity proportion. For crypto, we take the USD price from a public source and multiply by the rate to get HKD.
4. Update frequency and timestamps
Market prices refresh periodically, and each price shows its "last successful update time" so you can judge freshness. Because of caching and upstream latency, the displayed price may lag the true live market, especially during sharp moves. These figures suit general reference and conversion and should not be treated as an executable real-time quote.
5. Where jeweller reference prices come from
Where the site shows "per-shop buy/sell references," they are derived from international spot plus a small date-and-hour adjustment estimate. They are not any shop's official quote and are not executable. Actual dealing depends on branch policy, stock, melt loss (weight deduction), craftsmanship, fees and live market conditions, and must be verified directly with the shop or bank. We do not collect, manufacture or claim to own any jeweller's official quote.
6. Known limitations
- Prices are cached and may lag by tens of seconds to a few minutes.
- Upstream APIs occasionally go down; we then show the last successful data or an error message.
- Some instruments (e.g. platinum, XPT) may be unavailable due to data-source limits.
- All figures are public-market reference estimates, not official or executable quotes.
Related: About Us · How the gold price data updates and its limits · Disclaimer.