South Africa has become the largest economy in Africa. For the past two years, Nigeria has claimed the top spot, but a re-calculation using current exchange rates has placed South Africa back on top. The new calculations are based on the International Monetary Fund's gross domestic product numbers for the two countries in 2015.
Over the course of this year so far, South Africa's rand and Nigeria's naira have been moving in opposite directions against the dollar - for the rand a gain of around 16%, while the naira has lost a third of its value since effectively abandoning its peg to the US greenback.
But there's not much in it - at $301bn South Africa beats Nigeria by just $5bn. Both economies are at risk of falling into recession, as they both contracted in the first quarter of this year.