The JSE All-share index fell by 1.5% in early trade on Thursday, as concerns around the latest developments in the US-China trade war battered emerging market sentiment.
Earlier in the week US President Donald Trump threatened to raise tariffs on $200bn of Chinese goods to 25% from 10% on Friday.
"It looks very likely that the trade war is entering round 2," said Commerzbank in a morning note to clients. "This does not bode well for the trade talks which are supposed to be held in the next two days."
"It looks very much like a trade deal is almost off the table. A 'no deal' could mean two things: either a complete collapse or simply a deadlock of the negotiations."
The JSE was closed on Wednesday as SA voted. On Thursday morning, as markets reopened, the All Share index was down 1.53% at 57 156.35 points. The JSE Top 40 was down 1.64% at 50 860.00 points.
The rand, meanwhile, was changing hands at R14.40/$ at 10:15, down 0.23% on the day.
Almost all stocks in the JSE Top 40 were in the red on Thursday morning, with Sappi [JSE:SAP] the biggest loser - down 6.27% at R62.61. Heavyweight Naspers [JSE:NPN] was trading 1.6% lower at R3487.81.
The only Top 40 stock to rise in early trade was Gold Fields [JSE:GFI], which was up 2.44% at R55.42.
Embattled retailer Steinhoff [JSE:SNH] meanwhile, which is no longer in the JSE Top 40, was trading 17% down on Thursday morning after it released its long-delayed 2017 annual report on Tuesday evening.