"Significantly high trading volumes yesterday, 17 August 2021, due to large corporate actions - including a record day of value traded in Equities, trading R145 billion (vs  R71 billion in December 2017) - has resulted in the JSE experiencing significant delays in processing these trades on some of its systems. This has resulted in a delay in the start of trading for the JSE equity market," the JSE said in a statement.

The record-breaking trading volume was due to the implementation of a share swap deal between Naspers and Prosus this week, which allowed Naspers shareholders to swap their shares for newly created shares in Prosus. 

The transaction increased the number of tradeable shares in Prosus and shrank the number of Naspers tradeable shares.

This meant that Naspers now has a smaller weighting in the JSE's indices, and index-tracking funds had to sell their Naspers shares (and buy Prosus shares) to reflect this, said FNB Wealth and Investments head of research Chantal Marx.

This fuelled the record trading volumes on the JSE on Tuesday. Naspers' share price slumped 8% following the "rebalancing" - but also due to a fall in the Chinese digital giant's Tencent's share price on Tuesday. Prosus owns 28% of Tencent.  

According to the head of a large dealing desk, the JSE is seemingly struggling with "system issues" due to the record volumes.

By mid-morning on Wednesday, no transactions have been fed through to the JSE's broker deal accounting (BDA) system.

In a statement to clients, the JSE said the next update will be provided at midday. 

Fin24