Westpac Retains August RBA Hike Call on Sticky Core CPI

Westpac Banking Corporation reiterated its forecast for a Reserve Bank of Australia interest rate increase in August, following the release of the May Consumer Price Index data on June 24, 2026. The bank's analysis hinges on a trimmed mean inflation trajectory reaching 3.8% by the end of the second quarter and the identification of structurally sticky price pressures within the services sector, which are anticipated to outweigh any transitory effects from the Middle East conflict. This positioning places Westpac at the more hawkish end of the spectrum among major bank forecasters.

Context — why this matters now

The RBA's last official cash rate adjustment was a 25 basis point hike in November 2025, bringing the rate to 4.60%. Since then, the board has maintained a data-dependent stance, emphasizing the need for confidence that inflation is moving sustainably toward the 2-3% target band. The current macroeconomic backdrop is defined by resilient domestic demand and a tight labor market, with the unemployment rate holding near 4.2%.

The immediate catalyst for Westpac's sustained hawkishness is the May CPI print, which revealed accelerating momentum in underlying inflation measures. The distinction between one-off price adjustments and those reflecting broader cost pressures is the critical factor for policy. A direct fuel surcharge may eventually unwind, but a hairdressing price increase that mirrors rising operational costs signals embedded inflation expectations.

Data — what the numbers show

The six-month annualised trimmed mean rate accelerated to 3.5% in May, a significant increase from the 3.2% recorded previously. This metric strips out volatile items and is the RBA's preferred gauge of core inflationary momentum. The quarterly trimmed mean is projected by Westpac to hit 3.8% by the end of Q2 2026.

Housing inflation, which constitutes approximately 20% of the CPI basket, demonstrated pronounced strength. New dwelling costs posted their most substantial monthly gain since December 2022. This surge is largely independent of global energy price fluctuations and points to persistent domestic capacity constraints and supply chain issues within the construction sector.

Service sector inflation continued its ascent, contrasting with more volatile goods categories. The May data also included a notable example of transitory pressure: a spike in postal costs that subsequently reversed, demonstrating the type of movement the RBA can afford to overlook.

Analysis — what it means for markets / sectors / tickers

The persistence in housing and services inflation directly impacts interest rate expectations, steepening the short-end of the Australian government bond yield curve. Banks with large retail lending books, such as Commonwealth Bank of Australia (CBA) and National Australia Bank (NAB), may see net interest margin expansion in the near term if the RBA follows through with hikes. Conversely, rate-sensitive sectors like real estate (ASX:GMG) and consumer discretionary (ASX:JBH) face headwinds from higher borrowing costs potentially dampening investment and spending.

The primary counter-argument to Westpac's view is that the global disinflationary trend, led by moderating goods prices, will eventually overwhelm domestic service-sector pressures. the full economic impact of previous tightening has not yet been fully transmitted through the economy. Market positioning data indicates a growing short interest in Australian government bond futures, reflecting a hedge against further hawkish policy surprises.

Outlook — what to watch next

The next pivotal data release is the Q2 CPI report, scheduled for July 29, 2026. This dataset will provide the final confirmation of the trimmed mean trajectory ahead of the RBA's August 4 meeting. Traders will scrutinize the monthly CPI indicator for June, due July 21, for early signals.

Key levels to monitor include the 3.8% threshold for the quarterly trimmed mean. A print at or above this level would significantly bolster the case for an August hike. In bond markets, the yield on the three-year Australian government bond, currently near 4.0%, will be sensitive to any shifts in rate hike probabilities. The AUD/USD pair will also react to the evolving interest rate differential between Australia and the United States.

Frequently Asked Questions

What does sticky services inflation mean for the RBA?

Sticky services inflation indicates that price rises are becoming embedded in the domestic economy, driven by sustained wage growth and high operational costs for businesses. Unlike goods inflation, which can be eased by improved supply chains or a stronger currency, services inflation is less responsive to international factors and is therefore a greater concern for the RBA, requiring a more assertive monetary policy response to anchor expectations.

How does housing inflation affect the overall CPI reading?

Housing costs have a substantial weighting of roughly 20% in the Australian CPI basket. Accelerating inflation in this category, particularly for new dwellings, exerts significant upward pressure on the headline and core readings. Because these costs are driven by local labor markets, material costs, and regulation, they represent a persistent source of inflation that is largely decoupled from temporary global commodity shocks.

What is the six-month annualised trimmed mean?

The six-month annualised trimmed mean is a measure of core inflation that calculates the annualised rate of price change over a half-year period after excluding a set percentage of the most extreme price movements, both up and down. It helps to identify the underlying trend in inflation by filtering out temporary volatility, making it a critical data point for the RBA when assessing the medium-term inflation trajectory.

Bottom Line

Westpac's August hike call rests on entrenched core inflation momentum exceeding the RBA's tolerance.

Disclaimer: This article is for informational purposes only and does not constitute investment advice. CFD trading carries high risk of capital loss.