The JSE was lower on Thursday morning, tracking Asian markets on concern that the US's move to support Hong Kong protests could weigh on trade talks.

US President Donald Trump signed a bill on Wednesday that would support pro-democracy protesters in Hong Kong. The law requires an annual review of the trading terms between the US and Hong Kong. China said it would take “firm counter measures” against Trump's latest move, Reuters reported.

“The thinking goes that the bill is mostly symbolic and doesn’t affect the phase one trade deal. The Hong Kong bill only becomes a reason to take profits from this year’s equity bull market if China over-eggs its response. We think there is a low chance of that happening. China is shaking one fist while the other is outstretched for a handshake,” said London Capital Group head of research Japser Lawler.

Earlier, the Shanghai Composite was down 0.47%, Hong Kong's Hang Seng 0.22% and Japan's Nikkei 225 0.12%. 

At 11am, the JSE all share lost 0.41% to 55,942.3 points and the top 40 0.42%. Banks were down 1.34% and gold miners 2.01%. 

Kaap Agri was up 2.71% to R28.77. It said on Thursday that its revenue increased 29.1% to R8.5bn in the year to end-September, thanks to a 10.6% increase in the number of transactions.

Tharisa dropped 4.76% to R14. The resource company said on Thursday that operating profit dropped 66.6% to $24.2m in the year to end-September.