The Johannesburg Stock Exchange lost more than R3 trillion in market capitalisation during March, its worst monthly performance since the 2008 financial crisis. The all-share index’s market cap fell from R26.6 trillion at the end of February to R23.2 trillion by 31 March.
Why it matters: the collapse reversed the JSE’s 38% gain in 2025 and early 2026, pushing first-quarter returns negative just as South Africa’s borrowing costs were starting to improve.
What drove the sell-off
The escalating US-Iran war was the primary catalyst. Oil prices surging above $109 per barrel disrupted global risk appetite and hit South African equities through the energy channel. The South African 10-year bond yield jumped from 7.5% in mid-February to 9.21% by 31 March, a six-week rise that made equities less attractive relative to fixed income.
Hardest-hit sectors
Resource stocks declined as precious metal prices pulled back. Financials suffered from higher bond yields, and the banking sector alone shed more than R200 billion in value during the conflict. The all-share index recorded double-digit losses for the month.
Context
Old Mutual Wealth investment strategist Izak Odendaal noted that despite the rout, the equity benchmark remains “up about 30% over the past 12 months,” positioning it ahead of cash and inflation. The JSE had hit the historic 100,000-point milestone in 2025. Listed equities stood at 313% of GDP before the March collapse.
What happens next
Markets enter April with oil near $115 per barrel and Trump’s Tuesday deadline for Iran adding further uncertainty. Rising borrowing costs threaten South Africa’s fiscal position at a time when rates were only just reaching sustainable levels.