The South African rand fell sharply after the South African Reserve Bank (SARB) unexpectedly kept its benchmark interest rate steady, surprising most experts and sparking a currency sell-off.

During Thursday's trading session, the South African currency fell by up to 2.5% versus the US dollar before finishing 2.2% down at 16.76 per dollar, making it the world's worst-performing major currency of the day.

Meanwhile, South Africa's benchmark 10-year government bond rates rose 16 basis points to 8.96% as markets responded to the decision.

The central bank's Monetary Policy Committee opted to keep the benchmark policy rate at 7%, against most analysts' predictions of a 25-basis-point hike.

Four committee members backed keeping interest rates constant, while two advocated for a raise, per Bloomberg, which surveyed 20 economists, only 3 of whom expected a hold, with the rest predicting a 25-basis-point increase.