Some buyers on the JSE do not get to have an opinion. An index fund exists to own whatever its index owns, in the same proportions, so the decision about what it buys is taken somewhere else entirely. On Friday that decision was Stadio Holdings, and the share rose about 23% on roughly 22 million shares, against a normal day of a couple hundred thousand. The company had said nothing to the market since its interim results three weeks earlier.
What the 2 September notice actually changed
The instruction was published on 2 September, in the FTSE/JSE Africa Index Series quarterly review. Canal+, Greencoat Renewables, Stadio and Brait went into the All Share index, while Primary Health Properties and RCL Foods came out, all of it applied after the close on Friday 18 September and effective from the Monday. RCL ended Friday 11% lower on four million shares against a normal 95 000, and Primary Health Properties fell 4%.
The same review made one change to the Top 40, and it retired a household name. Woolworths came out and Aspen Pharmacare went in, the first time since 2011 that Woolworths has not been in the index of the JSE's forty biggest companies. Its market value has gone from R54.52 billion in January to R37.24 billion, while Aspen's has climbed to R66.77 billion over the same stretch. Woolworths now sits on the Top 40 reserve list, where the notice ranks it 45th. Its new chief executive, Sam Ngumeni, has been reorganising the retailer around Food, which he calls its primary growth engine.
Why free float decides the size of the move
Getting added is not the whole story, or every addition would have jumped. A tracker buys each holding at its index weight, and that weight rests on free float, the slice of a company actually available to trade rather than locked up with a controlling shareholder. The notice puts Stadio's free float at 70% and Brait's at 60%, and Brait rose 8.6% on Friday.
Canal+ and Greencoat joined the same index with almost nothing loose, 0.51% and 1.94% respectively, and the market barely registered them: Canal+ slipped 3.7% and Greencoat did not move at all. Which index also matters. Stadio went into the Small Cap and Shariah All Share indices too, and those are tracked by far smaller funds than the All Share, whose biggest tracker, the Satrix Alsi fund, runs R9.3 billion.
Premier is the precedent worth holding onto. Brait placed a block of Premier shares in 2024, which got it into the All Share that September; it jumped 26% on the Friday and closed 12% lower on the Monday. By late morning on Monday, Stadio was trading around 11.7% below Friday's close of R18.49.
