RBA Rate Hike to 4.6% Tests ASX as Oil and Fed Tighten Grip

A fourth hike, and a market that barely flinched

The Reserve Bank of Australia raised its cash rate by 25 basis points to 4.6% on September 29. It was the bank's fourth increase of 2026 and took the official rate to its highest level since November 2011.21 The nine-member board voted unanimously, and its statement warned that it would lift rates further if needed to stop high inflation from becoming entrenched.2629 The decision ended a two-meeting pause at 4.35% and brought this year's total tightening to a full percentage point.2330

The hike was not a surprise. Before the meeting, cash rate futures put the chance of a move at about 90%, and the big four banks' economic teams had all made a hike their base case.25 That pricing explains the share market's calm response. The S&P/ASX 200 dipped by as much as 0.22% after the 2.30pm announcement. It then rallied sharply in the last half-hour and closed 29 points, or 0.34%, higher at 8,709.3.2630

One outlet initially described the post-decision move simply as the ASX 200 "moving lower." It also called 4.6% the highest rate since 2015.27 Other coverage contradicts both points: the index ended the day higher, and the comparison point for the rate is late 2011.2130 The intraday dip was real, but the more important story is that the market bounced back.

Why shares rose on a rate rise

The answer lies in what Governor Michele Bullock said after the decision. In her press conference she said the board needed to see how the four increases fed through the economy, which signalled no rush to move again at the November 3 meeting on Melbourne Cup Day.30 The market rose about 0.3% while she was speaking, as investors took her remarks as dovish.24 She also told reporters that the board had weighed downside risks, including the housing market, and that a global surge in bond yields was "not worrying me at the moment."23

The split between the hawkish written statement and Bullock's more measured tone is the main source of disagreement among economists. ANZ's Adam Boyton read the unanimous vote and firm statement as grounds to keep forecasting a November follow-up.24 HSBC's Paul Bloxham also expects another hike in the fourth quarter, most likely in November after the third-quarter CPI release in late October.21 Commonwealth Bank economists went the other way. They said the press conference had raised the bar for another increase and that they expect a November hold, while calling the call finely balanced.22 AMP's Shane Oliver said the cycle was probably over, though the risk of more hikes had not gone away.30

The data have tipped the balance toward a pause, at least for now. A day after the decision, underlying inflation held steady at 3.6%, and markets cut the odds of a November hike to about 20%.22 Before the decision, the odds had been about 43%.23 Analysts are now looking at the December 7–8 meeting as the more likely date for any further move.22 On this evidence, Bullock's comments rather than the statement are the better guide to the near-term path, but the risk of another hike is still real.

Where the pain lands on the ASX

The headline index masks clear differences between sectors. On decision day, information technology led with a 4.6% gain, helped by profit upgrades and contract wins at companies such as Codan and Megaport. Materials rose 1% and consumer discretionary 0.7%.2123 Reports differ on the consumer sector: one account says property and consumer discretionary names led the immediate sell-off.29 Another says consumer discretionary doubled its morning gains by the close as traders scaled back their worst-case rate scenarios.30 Both can be true. Rate-sensitive stocks fell first and then recovered most strongly once Bullock had spoken.

The banks did less well. CommBank fell 0.8% to $150.27, and the other big four lenders were roughly flat.30 All four then passed the hike on in full to variable mortgage rates. Macquarie had already done so, effective October 15.2122 The ACTU estimated the increase adds about $110 a month to repayments on an average $731,000 mortgage.21 Xero's economist said the hike piles onto three earlier rises that had already hurt small-business sales.21

Before the meeting, analysts argued that the hike itself mattered less than the expected peak. Swaps were pricing about 40 more basis points of tightening beyond 4.6%.28 If that expected peak moves higher, real estate and other stocks that trade like bonds tend to be hit first.28 Investors in those sectors should watch the late-October CPI release more closely than the cash rate itself.

The Fed's own turn to tightening

The RBA did not act alone. On September 16, the US Federal Reserve voted 12–0 to raise the federal funds rate by 25 basis points to 3.75%–4%. It was the Fed's first hike since July 2023, and officials signalled another could follow.1 Chair Kevin Warsh said the committee had to be confident that underlying inflation was moving to target clearly and quickly enough, and that this standard had not been met.10 Sixteen of the 18 participants pencilled in at least one more increase this year.3

Minutes released on October 7 confirmed the unanimous support. They also showed some officials were worried that price rises driven by energy disruption and AI-related demand could spread more widely.2 However, the economic picture has changed since that meeting. August core PCE inflation came in at 3.0%, payrolls rose by only 29,000 in September, and unemployment edged up to 4.2%.6 Futures now put only about a 17% chance on an October 27–28 hike but about 70% on December.4 New York Fed President John Williams said he sees "no need for urgency."4

Both central banks are on similar paths. Each delivered a unanimous, well-flagged hike with hawkish language, and each now faces data that support waiting. That parallel matters for Australian shares. When the Fed and the RBA tighten together, there is less pressure on the exchange rate. The Australian dollar slipped to 69.93 US cents after the decision rather than rising.21 One commentator before the meeting argued that the RBA had little choice but to hike as the US dollar weakened.21

Oil: the variable neither bank controls

Oil is the main external force behind both decisions. Warsh said directly that a Fed rate hike cannot fix the lack of safe passage through the Strait of Hormuz, which he identified as the main factor keeping oil above $100.5 The Iran war began early this year, and the International Energy Agency has called the resulting closure of Hormuz the largest supply disruption in the history of the oil market.18 Brent peaked near $118 in late March, fell to about $70 by July, and climbed back above $100.18 Crude prices are up about 70% this year.15

The past week shows how unstable prices are. At least 12 attacks, attempted attacks or harassment incidents involving tankers were recorded around Hormuz between September 28 and October 5, the most in a single week since the war began.17 Brent jumped about 5% to roughly $105 on October 8. Reports that the White House had asked for options for further strikes on Iran set off selling in global bond and stock markets.11 Hurricane Isaias added to the pressure, with about 63% of US Gulf of Mexico output shut in.14

Prices then eased after President Trump said talks with Iran were productive and ruled out attacks before the November 3 midterms.19 Iran said it was reviewing a US response to a proposal that could reopen Hormuz within seven days.19 Some factors are limiting the rise: Gulf exports beat pre-war levels on several days in late September, and the G7 is releasing 100 million barrels of crude and diesel from reserves.20 Still, Brent settled near $104.72 on Friday.15 High freight and war-risk insurance costs help explain why it has been hard to push Brent firmly below $100.17

The reading

The RBA's September hike is best seen as part of a global response to an energy-driven inflation shock, not a purely domestic decision. The ASX's calm reaction makes sense because the move was already priced in and the Governor reassured markets. That calm depends on two upcoming events. The first is Australia's third-quarter CPI. The second is whether diplomacy reopens Hormuz before the oil risk premium feeds into inflation expectations again.

If both go well, 4.6% may prove to be the peak, and the rate-sensitive stocks that sold off on decision day could have room to recover. If Brent rises again, the hawkish statement Bullock played down will matter more. A December hike would then be the more likely outcome.