Premium/Discount Tracker — Methodology
Independent third-party calculation. We do not issue, custody, or trade these tokens. This page documents formulas, sources, denominations, limits, and change log.
OTSFA principle — One True Source for All. Every spot price on this tracker comes from the LBMA / LPPM auction (primary fix). Every token price comes from CoinGecko aggregated CEX/DEX trades. We do not adjust, smooth, or interpolate either side.
1. What this tracker measures
For each tokenized precious-metal product, we compute the percentage gap between its on-chain market price and the equivalent LBMA / LPPM spot fix for the underlying metal at the same point in time.
- Premium (positive %) — token trades above spot. Buyer pays more than the underlying metal would cost on the wholesale market.
- Discount (negative %) — token trades below spot. Buyer pays less, but this often reflects redemption frictions, liquidity gaps, or counterparty risk premia.
- Zero — token trades at parity with spot. Rare in practice.
2. Premium / discount formula
spot_equivalent = token_price_usd / oz_per_token
premium_pct = (spot_equivalent / spot_lbma − 1) × 100
premium_pct = (spot_equivalent / spot_lbma − 1) × 100
Where:
token_price_usd— last traded price in USD across all CEX/DEX venues, aggregated by CoinGecko.oz_per_token— troy ounces of physical metal backing one token. See denominations table below.spot_lbma— most recent LBMA Gold PM Fix or LPPM Silver Fix in USD per troy ounce (London auction).
Why divide by
oz_per_token first? Different issuers chose different denominations. PAXG = 1 troy oz. KAU = 1 gram (≈ 0.0321507 oz). Without normalisation, KAU would always look ~31× cheaper than PAXG even when there is no real premium. The spot_equivalent step converts every token to an apples-to-apples per-troy-ounce price.
3. Tokens tracked & denominations
| Ticker | Name | Issuer | Metal | oz / token | Custody |
|---|---|---|---|---|---|
| PAXG | PAX Gold | Paxos Trust (NYDFS) | Gold | 1.0000 | LBMA-accredited vaults, London |
| XAUT | Tether Gold | TG Commodities Ltd (Switzerland) | Gold | 1.0000 | Swiss vault |
| KAU | Kinesis Gold | Kinesis Money (Cayman) | Gold | 0.03215 | Allocated vaults (1 g/token) |
| XAUM | Matrixdock Gold | Matrixport (Singapore) | Gold | 1.0000 | LBMA-accredited vaults |
| PGOLD | PleasingGold | PleasingGold (Pacific) | Gold | 1.0000 | Allocated vault |
| KAG | Kinesis Silver | Kinesis Money (Cayman) | Silver | 1.0000 | Allocated vaults (1 oz/token) |
| XAGM | Matrixdock Silver | Matrixport (Singapore) | Silver | 1.0000 | LPPM-accredited vaults |
Not tokenized (yet) — Platinum (XPT), Palladium (XPD), and Copper currently have no live retail token with material liquidity. The LBMA / LPPM spot is collected for completeness on the comparison index but no premium calculation runs for these metals.
Denomination constants used in code
G_PER_OZ = 31.1034768 # troy ounce in grams (NIST) KAU oz_per_token = 1 / G_PER_OZ = 0.03215074656...
4. Spot reference (LBMA / LPPM)
We use the most recent fix at the moment of token-price fetch. London auctions publish twice daily for gold (AM and PM fix) and once daily for silver.
| Metal | Reference fix | Cadence | Currency |
|---|---|---|---|
| Gold (XAU) | LBMA Gold Price PM | Daily, ~15:00 London | USD/oz |
| Silver (XAG) | LBMA Silver Price (LPPM) | Daily, ~12:00 London | USD/oz |
| Platinum (XPT) | LBMA Platinum PM | Daily, ~14:00 London | USD/oz |
| Palladium (XPD) | LBMA Palladium PM | Daily, ~14:00 London | USD/oz |
Weekends and London bank holidays: no new fix is published. The tracker keeps the previous business-day fix and labels it accordingly.
5. Primary data sources
| Data | Source | Endpoint |
|---|---|---|
| Spot fixes | LBMA / LPPM | prices.lbma.org.uk |
| Token prices & market cap | CoinGecko public API | coingecko.com |
| Tokenized commodities aggregate | rwa.xyz | app.rwa.xyz/commodities |
| Tokenized gold category | CoinGecko categories | tokenized-gold |
| Tokenized silver category | CoinGecko categories | tokenized-silver |
| Issuer attestations | Direct from issuer pages | See individual issuer rows in table above |
6. Update cadence
- Token prices — refreshed once per day at ~02:14 UTC via the same cron that updates LBMA spot and ETF closes.
- Spot fixes — refreshed once per day, ~02:14 UTC, from
prices.lbma.org.ukJSON. - 365-day history — rolling window. Old days drop off the chart automatically as new days append.
- Files —
/data/gmri/tokens-current.json(snapshot) and/data/gmri/tokens-history.json(daily series). Raw JSON is public.
7. Arbitrage calculator
The calculator on the main tracker page applies the same spot reference to a hypothetical position.
metal_amount_oz = usd_amount / spot_lbma
token_units = usd_amount × (1 − fee_pct/100) / token_price_usd
token_equivalent_oz = token_units × oz_per_token
edge_oz = side == "buy_token" ? (token_equivalent_oz − metal_amount_oz) : (metal_amount_oz − token_equivalent_oz)
edge_usd = edge_oz × spot_lbma
token_units = usd_amount × (1 − fee_pct/100) / token_price_usd
token_equivalent_oz = token_units × oz_per_token
edge_oz = side == "buy_token" ? (token_equivalent_oz − metal_amount_oz) : (metal_amount_oz − token_equivalent_oz)
edge_usd = edge_oz × spot_lbma
The fee input lets the user model exchange fees, custody fees, or expected slippage. The calculator does not include: gas costs on chain, FX conversion, redemption fees charged by the issuer, or capital-gains tax. Treat the output as a ceiling, not a realised result.
Not financial advice. A positive "edge" on this calculator is a mid-market mathematical observation, not a tradeable opportunity. Liquidity, KYC frictions, withdrawal limits, and tax treatment will absorb most or all of the visible gap on real-world transactions.
8. Limits & caveats
- Asynchronous fixes. LBMA publishes once or twice daily. Token markets trade 24/7. A 3% gap measured on a Sunday is partly the absence of a new fix, not a real dislocation.
- CoinGecko aggregation. Token prices are volume-weighted across venues. Thin tokens (XAGM, PGOLD) can show jumps that reflect one large trade, not a market-wide move.
- Custody quality is not measured here. A token trading at parity with spot is not automatically safer than one at a 5% discount. Attestation cadence, auditor reputation, jurisdiction, and redemption rights matter and are not in this premium number.
- We do not include wrapper ETFs. Backed bGOLD, 21Shares physical gold ETPs, etc. are tracked on the GMRI comparison index, not here.
- Survivorship. Tokens that delist or lose CoinGecko coverage drop out. Historical premium series may not be reconstructable from this site alone for retired tokens.
- No backfill. If a fetch fails, we do not interpolate. The chart shows a gap until the next successful fetch.
9. Change log
- 23 June 2026 — v1.0 initial release
- Launched Premium/Discount Tracker with 5 gold tokens (PAXG, XAUT, KAU, XAUM, PGOLD) and 2 silver tokens (KAG, XAGM). 365-day rolling history. Daily refresh via cron 12590c93 alongside LBMA spot and ETF closes.
- 23 June 2026 — LBMA spot 365-day window
- Extended LBMA / LPPM history fetch from latest-only to a rolling 365-day window so the comparison chart shows a full year of context, not a single snapshot.
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Disclaimer. TrueSource Metals is an independent data and research platform. We are not affiliated with Paxos, Tether, Kinesis, Matrixport, PleasingGold, the LBMA, the LPPM, or CoinGecko. Numbers shown are for informational purposes only and do not constitute investment advice, an offer, or a recommendation. Past premium/discount behaviour is not predictive of future behaviour. Do your own due diligence.