Stocks closed lower, in line with emerging markets amid renewed trade war uncertainty, with bourse heavyweight Naspers among the biggest fallers.

At 1524 GMT the rand was 0.12 percent stronger at 14.6975 per dollar, not far off Thursday's close of 14.7150.

The rand has lost nearly three percent this week and is on track for its worst monthly performance in two years, as falls in the Argentine peso and Turkish lira this week produced shockwaves across emerging markets.

The rand largely ignored data on Friday showing South Africa's trade balance swung to a deficit of 4.66 billion rand ($317.40 million) in July, lagging market expectations of a surplus.

"It was very stable today. Not even our worse-than-expected trade balance impacted the rand," Wichard Cilliers, chief currency trader at Treasury One.

Government bonds firmed, with the yield on the benchmark paper due in 2026 closing down 6 basis points at 8.98 percent.

On the bourse, the Top-40 index was 0.35 percent lower at 52,464 points while the all-share index fell 0.23 percent to 58,668 points.

Naspers closed 2.51 percent lower at 3,266 rand after Tencent Holdings, in which it holds a 31 percent stake, lost $20 billion market value on the back of an intensified crackdown on online gaming by the Chinese government.

"Tencent and their biggest competitor make up 75 percent of the gaming market in China so this is certainly a big worry for them," said Kyle Burgess, portfolio manager at Nedbank Private Wealth.

South African insurer Old Mutual was down 1.84 percent to 30.40 rand after it reported no growth in half-year profit as higher taxes and unemployment hit consumer spending.