The Extreme Index
The Extreme Index is Extreme Banknotes’ own collector score from 0 to 10, shown on every banknote in our shop. It answers one question: how remarkable is this note? A score combines the story behind a note, how hard it is to find, how striking it looks, how old it is and the condition of the example we sell.
The Extreme Index is not a valuation or an investment rating. A 9.5 is not “worth more” than a 6.0; it simply has more history, drama or rarity packed into it.
The five ingredients
| Ingredient | Weight | What it measures |
|---|---|---|
| History & drama | 30% | The events behind the note: hyperinflation, war, occupation, revolution, new nations, famous people. |
| Scarcity | 25% | How rarely the note turns up, based on the rarity index of the Numista catalogue. |
| Wow factor | 20% | Visual impact and curiosity: astonishing denominations, unusual formats, standout designs. |
| Age | 15% | Older notes score higher, from modern issues to 18th-century paper money. |
| Condition | 10% | The grade of the note we sell, from Fine to Uncirculated or PMG-graded. |
Each ingredient is scored from 0 to 10, and the weighted total gives the Extreme Index, rounded to one decimal.
Special rules
- Hyperinflation notes score at least 8.0, because they record some of the most extreme moments in economic history.
- Record holders, such as the highest denomination ever circulated, score at least 9.5.
- Fantasy notes, which were never official government issues, are capped at 2.0.
How to read a score
- 8.0 and above: extreme. Hyperinflation giants, revolutionary assignats and record holders. Browse them in Most Extreme Banknotes and, above 8.5, Our Most Extreme Banknotes.
- 5.0 to 7.9: remarkable. Notes with a strong story or real scarcity. These listings include a full “Why it’s extreme” breakdown.
- Below 5.0: classic. Attractive, affordable notes, ideal for building a country or theme collection.
Examples from our shop
- Hungary 100 Millió B-Pengő 1946: 9.8. The highest denomination ever circulated, 100 quintillion pengő, from history’s worst hyperinflation.
- France 500 Livres Assignat 1793: 9.3. Paper money of the French Revolution, issued during the Reign of Terror.
- Romania 1000 Lei 1950: 5.9. An early communist-era note issued soon after King Michael was forced to abdicate.
- Uruguay 50 Pesos Uruguayos 2020: 3.9. A modern, attractive circulation note.
Of the 618 banknotes currently in stock, 85 score 8.0 or higher.
Frequently asked questions
Does a higher Extreme Index mean a higher price?
Not necessarily. Price depends on market demand and condition; the Extreme Index measures story and rarity. Some of our highest-scoring notes are surprisingly affordable.
Where does the scarcity score come from?
From the rarity index published by Numista, the largest online catalogue of banknotes and coins, which reflects how many collectors own a given note.
Can a score change?
Yes. If new catalogue information appears or we sell a note in a different grade, we update the score.
Subscribe to our emails
Be the first to know about new collections and exclusive offers.