BezantWhat the formula is
Take the ten largest economies in the world by nominal GDP, as ranked by the IMF in the April edition of the World Economic Outlook. From each economy take exactly one unit of its currency. If several economies share a currency, it enters once per economy: in 2026 the euro enters three times, for Germany, France and Italy. Add the ten units together at the European Central Bank’s daily reference rates and divide by ten. That is the price at which the issuer sells a bezant.
(1 USD + 1 CNY + 3 EUR + 1 JPY + 1 GBP + 1 INR + 1 BRL + 1 CAD) ÷ 10 = €0.5962
The composition is fixed for a year and changes only when the IMF ranking changes. The rates are public and free, published every working day around 16:00 CET, so any node, any buyer and any regulator can recompute the price to the fourth decimal. Every value of the past year is on this site as open data (price.json).
Why there are no weights
The obvious alternative is a weighted basket, like the IMF’s Special Drawing Right, where each currency counts in proportion to trade or reserves. Weights are better economics and worse governance: somebody has to sit in a room and set them, and then somebody has to be trusted to revise them. One unit of each currency is a rule with no dial. The only decision is the rule itself, and the ranking that feeds it belongs to the IMF, not to us.
The cost of a dial-free rule is that nominal denominations matter. A pound is worth more than a yen, so a pound counts for more of the sum. Today one pound is 19.5% of the sum, the three euros together 50.3%, the yen 0.1%. We accept this because the alternative is discretion, and because the effect is bounded: no single unit is more than a fifth of the price, and the composition still follows the world’s largest economies rather than anyone’s preference.
Why a sum of ten moves less than its parts
Currencies move against each other, not in step. When the dollar strengthens against the euro the pound often does not, and the yen may go the other way. A sum of ten units therefore moves less than most of the units in it, because the moves partly cancel. This is arithmetic, not a promise, and it can be checked on the record.
Twelve months, measured in euro
Range over 265 ECB trading days, 29 August 2025 to 11 September 2026: the difference between the highest and the lowest value, as a share of the average. The bezant line is the formula price; the others are each currency’s rate against the euro.
Measured in euro, the formula price stayed inside a corridor of 1.6% for a year, from €0.5898 on 27 January to €0.5992 on 20 July. Its annualised volatility was 1.5%, against 3.3% for the pound, 5.4% for the dollar and 8.4% for the real.
The honest part: half of the basket is euros
Three of the ten units are euros, and the price is quoted in euros. Half of the sum therefore cannot move at all when measured in euro, and that flatters the 1.6% figure. A world currency has to be judged from where its holders stand, so the fair test is to measure the same year in each of the other currencies and compare it with what that currency itself did against the euro.
The same year, measured in each currency
| Measured in | Bezant price, range | That currency vs euro, range |
|---|---|---|
| US dollar | 4.19% | 5.45% |
| Pound sterling | 2.68% | 4.14% |
| Canadian dollar | 3.75% | 4.42% |
| Yuan | 7.53% | 8.85% |
| Real | 13.04% | 13.82% |
| Yen | 9.12% | 8.78% |
| Rupee | 10.36% | 9.80% |
Same 265 days. Left column: the formula price converted into that currency at the ECB rate of the day. Right column: that currency’s own rate against the euro. A smaller number on the left means the bezant was the steadier thing to hold.
For a holder of dollars, pounds, Canadian dollars, yuan or reais the bezant moved less over the year than their own currency did against the euro. For a holder of yen or rupees it moved about the same, slightly more. Nobody in the basket was worse off than with a bet on any single foreign currency, and nobody was exposed to one. That is the property we were after: not a price that never moves, which no honest currency can offer, but a price that is never a bet on one country.
What the formula is not
- Not a peg. The formula sets the price at which the issuer sells. It does not promise that a bezant can be handed back for that amount, and it does not hold reserves to make such a promise. A bezant is not “equal to the basket”; its primary-sale price is computed from it.
- Not a floor. On any market the bezant may trade below the formula. What the formula gives is a ceiling: while the issuer sells at the formula, nobody will pay more elsewhere. That ceiling is what makes “buy it because it will rise” an empty sentence, and that is deliberate: a settlement unit is bought to be used, not to be waited on.
- Not a reserve. Because nothing is promised for redemption, nothing has to be kept in a vault, and there is nothing to run on. The price rule needs no custodian, only arithmetic.
What we will watch
Each April the IMF publishes a new ranking. If the ten largest economies change, the basket changes with them and the price steps once; we publish the new composition before it applies. Inside the year the only movement is the exchange rates themselves. The weekly sales window quotes the previous Friday’s fixing and holds it for the week, so a buyer always knows the price before the window opens.
Sources: ECB euro foreign exchange reference rates (data-api.ecb.europa.eu, series EXR.D.*.EUR.SP00.A), 29 August 2025 to 11 September 2026; IMF World Economic Outlook, April 2026, nominal GDP ranking. Ranges are (max − min) ÷ mean over the period; volatility is the standard deviation of daily log changes, annualised over 252 days. All values reproducible from price.json.