Methodology and data sources
Every useful number needs a definition. This page documents how weights, melt values, premiums, proceeds and market relationships are calculated.
Core measurement constants
- 1 troy ounce = 31.1034768 grams.
- 1 pennyweight = 1.55517384 grams.
- Purity is entered as a decimal fraction: 18K = 0.750, 14K ≈ 0.5833, 22K ≈ 0.9167.
- Fine gold weight = gross gold-bearing weight × purity.
Melt value and modeled sale proceeds
Melt value = fine gold grams ÷ 31.1034768 × gold price per troy ounce. Modeled proceeds multiply melt value by a buyer payout percentage and then subtract explicit transaction fees. This is an estimate, not a binding offer.
All-in premium
Net acquisition cost = merchandise + shipping + payment fees + tax − qualifying rewards. All-in premium percentage = (net acquisition cost − total metal value) ÷ total metal value × 100.
Correlation
The Correlation Lab aligns observations by date, calculates daily percentage changes for both series, then uses the Pearson correlation coefficient over rolling 30, 90 or 252-observation windows. It does not correlate raw price levels. Missing dates are excluded rather than filled with invented observations.
Market data
Daily gold and silver history is used under CC BY 4.0 or stated attribution terms from GoldPrice.com. Bitcoin history comes from CoinGecko. The S&P 500, DXY and 10-year real yield are imported from the openly licensed Aegean Intelligence market and macro package; its real-yield series is sourced from FRED and its market series use stated proxies. Each page displays the latest available observation; series may have different holidays and update delays.
Update policy
The scheduled updater runs once per day. Each source is imported inside a database transaction. If one source fails, its previous successful observations remain available and the failure is recorded without deleting good data.
Limitations
Spot and closing prices do not include product premiums, taxes, shipping, assay, refining or buyer spreads. Jewelry inputs do not authenticate metal or stones. Storage comparisons do not assess the strength of an insurance contract or custody arrangement. Historical relationships do not predict future performance.