The JSE's All Share Index rose 0.29% on Monday to reach 35 897.69 points – a historical mark – while the Top 40 Index also rose 0.26% to its best-ever level.
The two indexes of Africa's largest stock exchange have both jumped 12% since the start of the year.
The phenomenal growth surprised analysts, especially after 44 people were killed at Lonmin's Marikana platinum mine two weeks ago, of which 34 were gunned down by police.
Production at the world's third platinum producer has been at a standstill since the wildcat strikes for higher wages started on August 10.
"At first glance, it seems quite odd," said Richard Schellbach from Citigroup in Johannesburg. "The global economy is not doing well, and the South African economy is declining, or actually is not growing as much as we thought it would," he added.
Nedbank analyst Dennis Dykes said the news meant little in the current economic climate.
"As far as the JSE is concerned in terms of boasting, it is not necessarily a cause for happiness," he said.
Economic growth forecast
South Africa, the continent's largest economy, has had to review its economic growth forecast downwards by 1.5 percentage point to about 2.6% this year, the analyst said.
Heavily sensitive to conditions in Europe, the country has been hard hit by the global financial downturn.
The radical left of the ANC has consistently insisted on the nationalisation of mines and redistribution of wealth. Such constant manoeuvring would usually unnerve investors.
Meanwhile the Lonmin strikes have highlighted the dismal conditions that mineworkers face, which could spark similar protests at other mines in the sector.
Some brokers however point out the Marikana unrest has dragged down the exchange rate of the rand. This in turn favoured exporters, especially of raw materials, which are priced in dollars.
Dykes also highlighted external factors, like the US Federal Reserve Bank's upcoming symposium at Jackson Hole or the European Central Bank's expected actions to regulate the eurozone crisis.
Despite troubles in South Africa's mining sector "all the other sectors you don't necessarily think of have done exceptionally well" on the JSE, said Schellbach. Many companies in healthcare, general retailers and media were "well-managed and prudent", he added.
"The local consumer is still able to borrow, he is still able to spend," says Ryan Seborne of 36One asset management. "The balance sheets are in a good shape."
Shaun Murison of IG Markets South Africa agreed.
"The recent retail trade sales figures released, show year-on-year growth of 8.3%, which has been reflected in good earnings and consensus beats in the individual company results, supporting the local and foreign investment within the sector," he said.
Share prices of retailers Woolworths, Foschini and Mr Price rose by 40% since January, he pointed out.
"This has helped offset the drawdown of a heavy resource sector suffering from a multitude of problems ranging from violence to [weak] demand." – AFP