At 0625 GMT, the rand traded at 16.9875 per dollar, 0.16% weaker than its close on Tuesday, giving some up gains made in the previous session as caution toward safe-haven assets ahead of the U.S. presidential debate kept some risk currencies in favour.
Trump and Biden battled fiercely over Trump's record on the coronavirus pandemic, healthcare and the economy in a chaotic and bad-tempered first debate marked by personal insults and Trump's repeated interruptions.
"A lack of liquidity in emerging markets as a whole, driven by pre-US presidential election caution, is causing exaggerated moves in the currency, giving rise to the current volatility," said Bianca Botes, executive director at Peregrine Treasury Solutions.
On Wednesday, local focus will be on a slew of economic data including August consumer price inflation and trade balance figures.
In fixed income, the yield on the benchmark government bond due in 2030 was down a single basis point to 9.475%.
(Reporting by Olivia Kumwenda-Mtambo; editing by Carmel Crimmins)