A back-to-back hike would extend the Australian dollar’s rate advantage and keep front-end yields elevated, while any hint that November is the last move could trigger a pullback in both. Fuel is the key transmission channel, so oil prices remain central to the outlook: further crude gains would deepen the pass-through into services and strengthen calls for more tightening. Australian equities, particularly rate-sensitive sectors such as property and consumer discretionary, face added pressure if markets begin to price a longer hiking path.---Earlier:ING lifts AUD/USD target to 0.71 as it backs a 25bp RBA hike next week---Fuel is no longer just a petrol-station problem for Australia’s inflation, and Natixis expects the RBA to respond again next week.Summary:September CPI rose about 0.8% m/m and 4.3% y/y, above forecasts of 0.7% and 4.2%Energy added about 0.3 points to the monthly rise, while travel contributed around 0.43 points, its most since December 2025Garcia Herrero sees the energy shock passing through to the broader basketThe Q3 trimmed mean edged up to about 3.7%, diverging from the RBA’s August forecast of a peak in Q2Hauser and Bullock comments reinforce the RBA’s low tolerance for persistent inflationNatixis expects a back-to-back hike on 3 November, with later decisions highly data dependentAustralia’s September inflation data delivered a sharp upside surprise that is likely to push the Reserve Bank of Australia into a back-to-back rate hike at its meeting on Tuesday, 3 November. That is the view of Alicia Garcia Herrero, chief economist for Asia Pacific at Natixis and one of the more closely followed analysts of the RBA.Headline consumer prices rose about 0.8% in September from August and around 4.3% from a year earlier, both ahead of consensus forecasts of 0.7% and 4.2%. Garcia Herrero said the print surprised the market as well as the central bank.The detail is what concerns her most. Energy added roughly a third of a percentage point to the monthly increase, but travel was the single largest driver, contributing around 0.43 percentage points, its biggest contribution since December 2025. Travel prices are closely tied to fuel costs, so Garcia Herrero said the data suggest the energy shock has begun to filter through to the wider basket of goods and services. She described this as a warning sign for policymakers.Underlying inflation is also moving away from the path the RBA expected. The trimmed mean, the central bank’s preferred core measure, rose to about 3.7% year on year in the third quarter, edging up from the second quarter. In August, the RBA had projected that the trimmed mean would peak in the second quarter and ease back towards 3.3% by the end of 2026. The latest reading widens the gap between that forecast and the actual inflation path.Garcia Herrero linked the data to recent comments from RBA officials. Deputy Governor Andrew Hauser recently described the inflation outlook as having deteriorated materially. Governor Michele Bullock told a parliamentary hearing this week that the central bank will not tolerate inflation remaining persistently high. Against that backdrop, Garcia Herrero expects the RBA to favour another hike next week.Beyond November, she expects policy to become more finely balanced. The RBA is likely to keep a hawkish tone while inflation remains elevated. However, signs of an easing labour market and slowing household spending under higher interest rates mean subsequent decisions are likely to be highly data dependent. This article was written by Eamonn Sheridan at investinglive.com.