As doubts continue about the durability of “fiat” money economies, Stanley Gibbons, the firm famed in the stamp collecting business, has rolled out a rare coin index showing prices having risen 248 per cent since 2002, an compound annual growth rate of 13.3 per cent.

The Rare Coin Index, giving a representative sample of 200 rare British coins, taken from the standard catalogue of UK coins, is designed to capture growth in pieces ranging £225,000 to £5,000. To give one of the strongest examples, a 1247-1272 Henry III gold penny with sceptre mark fetched a price of £225,000 this year, a jump of 309.1 per cent over 10 years.

The best performer in the index- a 1663 Charles II gold guinea – shows a CAGR of 27.8 per cent, Stanley Gibbons said.

The data is based on published auction realisations for the last 10 years.

The figures will intrigue people at a time when conventional cash sometimes carries a negative yield amid ultra-low real interest rates. As reported recently by this publication, concerns about “fiat” money banking systems – where money is not backed by physical assets such as gold or silver – has reignited interest in assets such as gold.  

“Whilst, of course, past success and sustainability cannot guarantee future performance, the strength and consistency of this index substantiates what we are seeing in the market and have been seeing for some time” said Stanley Gibbons Investment Director, Keith Heddle.

Other measures of rare, collectable items show mixed results over different time periods. For example, the Liv-ex Fine Wine 50 index of prices fetched for fine wines (mostly from Bordeaux) shows they gained more than 70 per cent over five years, but down over the year by 22.8 per cent. The HAGI indices of classic cars – marques such as Ferrari and Porsche – show that between January and April this year, prices rose on average by 7.82 per cent. Prices have outperformed the US S&P 500 index of equities over the past decade.