The Fed's Credibility Trap: When Energy Shocks Meet Rate Hikes

The Fed's meeting on Thursday will not be the first time this year that an energy shock and a rate decision collide. It will be the most consequential.

Brent crude oil is trading near $104 a barrel, close to its highest level since May. The price has been propped up since spring by the U.S.-Iran conflict, which disrupted the Strait of Hormuz, the chokepoint through which roughly 20% of the world's oil supply flows. The strait has since reopened partially, but production in the Middle East remains below pre-conflict averages, and global inventories have fallen by an estimated 400 million barrels so far this year. Energy is not back to normal. Neither, apparently, is the Federal Reserve prepared to pretend it is.

Fed Chair Kevin Warsh told investors at Jackson Hole on 28 August that the central bank still has "work to do" on inflation. He did not commit to a specific move, saying he was "committed to a discipline, not to a decision." The market heard something closer to a promise. Within days, the probability of a quarter-point rate hike at the September 15-16 meeting climbed above 55%, nearly double where it had stood before the symposium. The federal funds rate, held steady at 3.50%-3.75% since late 2025, could move higher for the first time in over a year.

The trouble is that nobody quite agrees on why.

What the energy shock is, and what it is not

Central banks have a simple framework for thinking about supply-driven price rises. The initial spike in energy costs is a "first-round effect": it pushes up headline inflation for roughly twelve months, then falls out of the annual comparison unless prices keep climbing. What policymakers actually fear is the "second-round effect" — higher energy bills feeding into wage demands, which feed into prices, creating a self-reinforcing spiral. The first shock the market absorbs; the second the central bank must stop.

This distinction matters because the current energy shock looks different from the one in 2022, when oil briefly touched $125 a barrel and the Fed lagged behind. At that point, labour markets were tight, growth was strong, and policy had barely tightened. Today the picture is reversed. Unemployment sits at 4.1%, described by Warsh as "consistent with full employment," but job growth has softened from earlier this year. The economy is resilient, not overheated. Inflation expectations, the barometer of whether a shock becomes embedded, remain "well anchored," by Warsh's own reading.

To be sure, the data is not unambiguously cool. Headline PCE inflation stood at 3.7% in July, well above the Fed's 2% target. Core PCE, which strips out food and energy, was 3.3%. That is the part that keeps policymakers awake. Core consumer prices, as measured by CPI, rose 2.5% over the year ending in July, close to the target but not convincingly at it. Warsh pointed out that 54% of the goods and services in the PCE index showed annualised price increases above 3% over the past twelve months. A single headline number, he argued, does not tell the whole story.

The August CPI report, due on Friday 11 September, is the last major inflation gauge before Thursday's decision. Consensus expects a 0.4% monthly rise in headline CPI, with core ticking up 0.2%, near 2.4%. A reading in line with expectations would neither confirm cooling trends nor signal a fresh acceleration. It would leave the Fed exactly where it is: committed to a target it has not yet reached, with an economy that can tolerate a little more pain but is not begging for it.

Why credibility matters more than the data

The hawkish turn from the Fed, the ECB, and the Bank of Japan is not purely data-driven. It is partly about institutional memory. After the 2022 energy shock, the ECB was criticised for being too slow to respond. In June it raised rates by 25 basis points, explicitly referencing the lessons of four years earlier. The ECB's deposit rate now stands at 2.25%. The Bank of Japan also tightened, driven by its own domestic labour shortages. Even the Bank of England, which has held steady at 3.75%, warned that the conflict could push inflation as high as 3.5% by July and signalled it "stands ready to act."

The Fed's situation is more delicate. It has held rates unchanged since December 2025, delivering neither the cuts that markets initially expected this year nor the hikes that some officials have advocated. The July meeting produced a 9-to-3 vote to hold, with three members wanting a quarter-point increase. Warsh's predecessor had built the Fed's credibility on a clear, data-dependent framework. Warsh has now scaled back forward guidance, arguing that such signposts "can distort market signals and inhibit the Fed's flexibility." What he offers instead is a promise of discipline and a refusal to be pinned down on a specific date.

The credibility trap is this: if the Fed holds rates while inflation remains above target and oil nears $105 a barrel, markets may conclude it is being dragged by political pressure — President Trump has been publicly demanding rate cuts, calling on the Fed to "be patriots." A hike, even a half-measure one, demonstrates independence. It also risks being exactly the wrong medicine for a supply shock. Treasury Secretary Scott Bessent has argued that raising rates in response to an energy supply disruption, without evidence of second-order effects, is inappropriate. He may be right. But central banks do not move on what is appropriate; they move on what is credible.

What it means for investors

The mechanical question is which way the FOMC votes on Thursday. The useful one is what a hike — or a hold — tells investors about the path ahead.

A rate increase, even a modest 25 basis points to 3.75%-4.00%, signals that the Fed views inflation as the binding constraint. That matters for equities because it implies rates may stay higher for longer than the easing cycle that markets entered 2026 expecting. The S&P 500 is just 0.7% below its mid-August record high, but the benchmark 10-year Treasury yield has climbed to nearly 4.8%, approaching the 5% level that historically weighs on stock valuations. Higher yields increase the cost of capital for businesses and make bonds a more attractive alternative to equities. Growth stocks, whose value depends on future earnings discounted back to the present, are particularly sensitive to this mechanism.

The sectoral effects are already visible. The U.S. airline ETF fell 13% over two weeks in August as fuel costs rose. Technology, which has been the engine of market returns, faces headwinds from both higher yields and the energy bill that AI data centres are starting to incur. On the other side, energy producers such as Exxon Mobil and Chevron have gained ground, and the EIA expects U.S. retail diesel prices to average over $5 a gallon this year. The shock creates winners and losers; the question is whether it is transitory or structural.

A stagflationary outcome — rising prices and weakening growth — would be the worst case. Goldman Sachs has warned that the probability has increased, though the EIA expects oil to gradually fall to an average of $74 a barrel in 2027 as Middle Eastern production recovers and inventories rebuild. The EIA's forecast, finalised on 3 September, does not account for events this week. Geopolitical risk is not a number that can be ploughed into a model.

The investor's task is not to predict Thursday's decision. It is to understand that the Fed's credibility is now the variable that matters more than any single CPI print. A hike would confirm that the central bank is willing to tighten into a supply shock to protect its inflation mandate. A hold would leave open the question of whether it can do so later without losing the initiative. Either way, the era of falling rates that many investors entered this year hoping for looks increasingly unlikely. The structural implication is simple enough: in a world where energy costs have jumped and central banks have shifted from cutting to potentially hiking, the valuation assumptions underlying much of the current market may need revisiting.