Gold is up nearly 15% this month, given fresh impetus by the US Treasury’s unexpected intervention in the bond market last week. A gauge of returns on South African precious-metal mining stocks is on track for its biggest monthly jump in at least two decades as gold and platinum prices recover from a steep slump. Key points and original sources are listed below.

• Gold is up nearly 15% this month, given fresh impetus by the US Treasury’s unexpected intervention in the bond market last week.S1

• A gauge of returns on South African precious-metal mining stocks is on track for its biggest monthly jump in at least two decades as gold and platinum prices recover from a steep slump.S2