South Africa's central bank is leaning on London to finish a job the local market has largely already done. The Reserve Bank says LCH SwapClear, the London Stock Exchange Group's clearing house, plans to convert all outstanding Jibar-linked derivatives contracts into Zaronia-linked instruments on 21 November.
Jibar, the Johannesburg Interbank Average Rate, is the reference rate South African lenders have priced off for decades. Zaronia, the South African Rand Overnight Index Average, is its replacement, and unlike Jibar it is based on actual transactions, which puts it in the same family as the euro and sterling overnight rates that replaced Libor.
A hard stop at the end of December
The clock is not negotiable. On 3 December 2025 the Reserve Bank announced that publication of all tenors of Jibar will permanently cease immediately following a final publication on 31 December 2026. ISDA confirmed shortly afterwards that the announcement was an Index Cessation Event under its 2021 interest rate derivatives definitions, and the fixed spread adjustments relevant to the Zaronia-based fallback arrangements were published.
LCH set out its approach in a member circular in February. Any cleared Jibar contract still outstanding at the point of conversion, and relying on a fixing that occurs after 31 December 2026, falls in scope, and each one is converted into a Zaronia equivalent. The Reserve Bank says the November event follows a discount curve switch LCH already completed in April, and will move the existing cleared contracts onto a newly constructed Zaronia curve.
The gap is offshore, not at home
The reason for the London route is jurisdictional. South African market participants are bound by a domestic directive prohibiting the creation of new Jibar-linked contracts. Offshore participants are not, and their transition has lagged the local market accordingly. Zaronia-linked swaps made up about 30% of total rand volumes registered in July, up from 20% the previous month, on the central bank's own figures, even after the UK regulator said in July that affected firms should already be well advanced in their transition plans.
Converting the cleared book in a single event does in one day what persuasion has been doing slowly. Every cleared Jibar position that survives to 21 November becomes a Zaronia position, whether or not the holder had got round to switching it. What is left after that is the uncleared, bilateral corner of the market, and six weeks before Jibar is published for the last time.
