The RBA's Unfinished Inflation Fight, and What It Means for the Australian Trade

The Reserve Bank of Australia has done something few central banks manage: reversed from cutting to hiking within a single cycle. After easing rates three times in 2025, the RBA raised its cash rate on three consecutive occasions in early 2026 — to 4.35% by May — then paused. Inflation, the cause of the reversal, has not cooperated by going away. The trimmed mean, the RBA's preferred measure of underlying price pressure, stood at 3.6% in July. The bank's own forecast sees it staying above 3% until mid-2027. That is a different world from the American one, where the Federal Reserve has been easing from 5.5% down to around 3.6%. The divergence is not temporary. It is reshaping capital flows, currency values, and the economics of an entire market that American investors can reach with one ticker.

The RBA's problem is structural rather than cyclical. To be sure, headline inflation eased to 3.5% in the twelve months to July, down from 3.8% in June. The trouble is that the softening comes almost entirely from tradable goods — electricity, which surged after government rebates expired but is now moderating, and fuel, which will ease further as the federal excise relief unwinds. What matters to the central bank is what remains. Non-tradable inflation, the domestic costs the RBA can actually influence through interest rates, sits at 4.4%. Housing drives it: rents up 3.6%, new dwelling costs up 5.7%, with builders passing on labour and materials costs that have nowhere else to go. Services inflation ticked up to 3.7%. Minimum wage increases in July pushed meals and takeaway food prices up by 4.5%. These are not one-off items. They are the cost of a tight labour market in an economy where medium-term productivity growth has been downgraded to 0.7% a year, from 1%, as the government's care sector expands and mining underperforms. The economy can grow at roughly 2% without generating new inflation, Assistant Governor Sarah Hunter said. That is a low ceiling for a population that wants more.

The consequence of a central bank that is tightening while others are easing is immediately visible in the currency. The Australian dollar has appreciated roughly 10% in the first half of 2026, from a 2025 average of 0.64 to just under 0.71 against the dollar. AMP, a wealth manager, sees it settling between 0.70 and 0.75, with a possible spike higher. Yield-seeking capital is not the only driver; the AUD had been undervalued after previous cutting cycles, and elevated commodity prices from AI infrastructure and electrification demand have lent additional support. But the interest-rate differential does the heavy lifting. A stronger Australian dollar performs a kind of stealth tightening. It dampens imported inflation, which helps. It also shrinks the trade balance, drags on GDP, and makes export-heavy sectors from mining to tourism less competitive. The RBA's own modelling suggests a 10% real appreciation reduces growth by 0.3 percentage points after 18 months. So the policy the RBA is trying to engineer through rates is being partially accomplished through the exchange rate. And partially undermined, because that same appreciation is one reason the July CPI eased to 3.5% at all.

American investors reach this story most directly through the iShares MSCI Australia ETF, which trades under the ticker EWA on the New York Stock Exchange. The fund tracks large- and mid-cap Australian companies, returning 10.4% over the year to June 2026. Its heaviest holdings are the Big Four banks, the miners, and the supermarkets. These categories react very differently to higher rates and a stronger currency.

The banks — Commonwealth Bank, Westpac, National Australia Bank, and ANZ — occupy an uncomfortable position. Rising rates ought to help them. They pass increases to borrowers quickly. Deposit rates, by contrast, lag and fragment as the banks compete for funds with promotional term deals. The net result has been margin compression rather than expansion. Commonwealth Bank's net interest margin fell four basis points to 2.04% in its most recent half. Westpac's dropped six basis points to 1.89%; ANZ's headline margin fell one basis point. Only NAB achieved a three-basis-point lift. The banks' own economists are equally divided on what comes next. NAB expects a further hike to 4.6% in September; CBA and ANZ lean toward November; Westpac forecasts nothing more. A bank's research desk is not an oracle, but it is a revealing mirror of internal uncertainty.

The miners face a different set of forces. BHP recently overtook Commonwealth Bank as Australia's largest listed company, riding the price of copper. Higher demand from AI data centres and electrification is a structural tailwind that a domestic rate cycle cannot touch. A stronger Australian dollar, however, reduces their revenue when measured in local terms. For American investors, the currency translation works the other way: a rising AUD erodes the dollar return on Australian equity. What is a 10% Australian-market gain becomes roughly 3% after currency translation, when the AUD has already risen 10% against the dollar. The timing of any further appreciation matters.

This brings the argument to its practical point. The RBA's higher-for-longer stance creates a genuine interest-rate differential, and that differential is real money flowing into the Australian dollar. The currency is doing much of the monetary policy work that the RBA intended to do through the cash rate. If inflation proves as sticky as the bank's own forecast suggests — trimmed mean above 3% until mid-2027 — the differential is likely to persist. A persistent differential means a persistently firm AUD. For American investors holding EWA or similar Australian-exposure vehicles, the currency tailwind may have already done most of its work. Further AUD appreciation compresses dollar-denominated returns, while the very bank stocks that are supposed to benefit from higher rates are watching their margins narrow. The miners that have driven Australian market leadership face headwinds from the same currency strength.

The inverse case is worth considering. The RBA has held rates at 4.35% since August, and its August minutes describe financial conditions as "somewhat restrictive". Inflation forecasts are not commitments. If the July data's softening proves less transient than the bank fears, the RBA may pivot to cuts sooner than its own projection admits. That would weaken the AUD, relieve pressure on borrowers, and restore the currency tailwind for dollar-based investors. It would also confirm that the hiking cycle has been shorter and less consequential than the current tone suggests.

The question for the American investor is not whether Australia's inflation is sticky. The evidence says it is. The question is whether a fund whose returns are already being trimmed by currency strength deserves a place in a portfolio built around the dollar, and whether the banks and miners inside it are priced for a scenario that may be reversing even as it unfolds.