Gold has returned to the international monetary system. Over 50 years ago, US President Richard Nixon “closed the gold window” (ended the dollar’s fixed-rate convertibility into gold), and the world moved on from its obsession with precious metals. A new era of fiat currency had begun. But now, fiat money is being challenged by fiscal worries and new technology (blockchains/distributed ledgers), and the price of gold has reached all-time highs, above US$2,400 per ounce.

Goldbugs, of course, argue that the metal remains an ideal investment for preserving value over the long term. But it is a mi...