25/09/2026
This Rate Hike Isn’t Really About Your Bond.
The immediate impact of higher interest rates is easy to calculate. The bigger story is why rates are rising in a weak economy, and how that decision quietly influences property supply, affordability, confidence and the cost of living long after the MPC announcement.
When interest rates go up, the conversation usually starts and ends with one question: How much more will my bond cost?
But I think that misses the more important story.
A 25-basis-point increase is relatively modest in isolation. On a R1 million, 20-year variable-rate home loan priced at prime, the increase is approximately R168 a month. On R1.5 million, it is around R253.
The really interesting question is why rates are being increased at all when the South African economy is hardly overheating.
Real GDP contracted by 0.2% in the second quarter, fixed investment has weakened and manufacturing has been under pressure. This is not a case of South Africans spending wildly and creating too much demand.
The concern is what happens after the fuel-price shock.
Oil and fuel can push up transport costs. Transport costs can work their way into the price of delivering goods. Businesses may then increase prices to recover those costs. Employees start expecting higher inflation and negotiating accordingly. Services such as transport, insurance, rentals and other household expenses can begin adjusting too.
At that point, what started as an oil problem becomes a broader inflation problem.
That distinction matters because the Reserve Bank cannot lower the oil price. What it can try to do is stop temporary inflation from becoming something households and businesses begin to regard as normal. With the Bank now operating around a 3% inflation target with a one-percentage-point tolerance band, credibility around that target has become increasingly important.
There are some property effects here that receive far less attention.
The first is that higher rates can reduce housing supply as well as demand.
Developers borrow money too. Higher financing and working-capital costs can make marginal projects harder to justify. If fewer homes are developed today, the consequence can be tighter supply several years from now. We have seen this dynamic in previous higher-rate environments.
The second is what I call the “stay-put effect”.
A homeowner may be perfectly capable of servicing their existing bond but reluctant to sell because moving means taking out a new loan at today's higher rate. The result can be fewer properties coming onto the market, even though there are still people who want to move.
Third, the people most affected by an inflation shock are not necessarily the people with the biggest bonds.
Many lower-income households have little or no mortgage debt, so the repo-rate increase itself may barely touch them directly. But fuel prices filter into taxi fares, food distribution and commuting costs. The research notes that minibus-taxi fares were already 13.1% higher year on year in June and July.
That is an important reminder that the headline interest rate and the lived cost of inflation are not the same thing.
There is one final point worth considering.
A small increase today may actually be intended to reduce the risk of larger or more prolonged increases later. If the Bank can prevent higher inflation expectations from taking hold, the argument is that it may avoid having to do considerably more damage to borrowers further down the road. The supplied assessment identifies exactly this credibility trade-off as one of the central issues facing the MPC.
So I would not look at this decision simply as another few hundred rand on a bond.
Interest rates influence whether people buy, whether they sell, whether developers build, whether businesses invest and, perhaps most importantly, how confident people feel about making their next financial move.
The number announced by the Reserve Bank may be small. Its ripple effects rarely are.
