The Johannesburg Stock Exchange will introduce new caps to help investors rebalance weightings after a stock swap between Naspers Ltd and Prosus NV.
Effective from September, the capping level for the SWIX All Share Index and SWIX Top 40 Index will fall to 6% from 10%, according to a statement from the bourse.
The interim measure is designed to align the companies’ combined weighting in key indexes to prevailing levels, JSE said.
The exchange will seek a permanent solution as quickly as possible after a consultation period following publication of a white paper in August.
The deal between South Africa’s Naspers and its spin-off Prosus this week caused havoc, with the JSE forced to delay opening by hours on Wednesday amid the rush of rebalancing trades.
“It is important to avoid a temporary structural dislocation in index weightings,” according to the JSE statement.
Naspers is Africa’s largest company by market value. The company’s 31% stake in China’s Tencent has helped to drive up its capitalization in recent years.