For decades, a familiar portfolio promise was that high-quality bonds would rise, or at least remain stable, when equities fell. Inflation has made that promise unreliable. Reuters reported that some U.S. investors are making more room for commodities, infrastructure, private credit and other inflation-sensitive assets after repeated periods in which stocks and bonds moved down together.
The reconsideration is rational, but the strongest conclusion is narrower than “bonds no longer diversify.” A nominal bond is exposed to inflation, interest rates and duration, while an equity claim is exposed to earnings and valuation. Whether their prices move together depends on which macroeconomic force is changing those inputs. The hedge is state-dependent.
That distinction matters because replacing bonds can solve one historical problem while creating a less visible one. Commodities may respond directly to an inflation shock. Private credit may display smoother prices. Neither automatically provides the daily liquidity, transparent valuation or recession sensitivity of a Treasury security.
The correlation changed because the shock changed
When inflation rises because demand and real growth are strong, companies may sell more and improve cash flow even as bond yields rise. Stocks can absorb higher rates if the growth news is sufficiently favorable. When inflation instead comes from an adverse supply shock — energy scarcity, tariffs or a production bottleneck — expected cash flows can weaken while discount rates rise. Nominal bonds and equities can then lose value together.
Federal Reserve researchers describe this as a time-varying relationship between inflation and growth. Their FEDS paper finds that, in periods of “good inflation,” higher expected inflation can coincide with tighter corporate credit spreads and higher equity valuations; in “bad inflation” periods, those effects weaken or reverse. The paper is staff research rather than an official Federal Reserve forecast, but its mechanism explains why a single long-run correlation is an incomplete portfolio assumption.
The current environment offers a concrete test. The Treasury Borrowing Advisory Committee's May report said an energy-price surge had lifted short-term inflation expectations and prompted hawkish repricing in global rates markets. It also noted that longer-term inflation expectations remained relatively stable. That combination is important: a near-term supply shock can pressure duration without proving that long-run inflation credibility has collapsed.
Income and insurance are different bond jobs
A bond allocation can perform at least four jobs: produce contractual income, preserve liquidity, match future liabilities and offset a growth shock. Duration helps the fourth job when a recession lowers expected policy rates and inflation. It hurts when inflation or the term premium rises. Short Treasury bills preserve liquidity and reduce duration exposure, but they offer less upside if rates fall sharply. Inflation-linked bonds protect principal from measured inflation, but their market price still moves with real yields.
This is why the question “Do bonds still work?” is too broad. A ladder held to maturity may deliver the cash flows it was bought to provide even if its quoted price falls. A long-duration fund bought as equity insurance is making a different wager: that the next shock will reduce nominal yields. An investor can reasonably keep the first role while reducing confidence in the second.
The counterargument deserves weight. Persistent fiscal borrowing, uncertain inflation and a higher term premium could keep long yields elevated even during weaker growth. In that regime, duration may remain an imperfect hedge for longer than models calibrated to the post-2000 period suggest. The correct response is to specify the bond's job and failure condition, not assume that past negative correlation will return on schedule.
Alternatives import risks the allocation label hides
Real assets and commodities can improve exposure to supply-driven inflation, but their protection is selective. Commodity futures depend on the particular commodity, curve structure and roll costs. Infrastructure equities may have inflation-linked revenue, yet financing costs, regulation and equity-market sentiment still matter. These assets can diversify a nominal bond portfolio without becoming a universal substitute for safe collateral.
Private credit introduces a different trade. Loans with floating rates may protect income when policy rates rise, and infrequent appraisals can make reported returns look less volatile than traded bonds. But borrowers are often below investment grade, valuations are less continuous and redemption rights can be constrained. The Federal Reserve's May Financial Stability Report said redemption requests increased at some semi-liquid private-credit vehicles and that most affected managers used their right to cap redemptions. The Fed judged the broader financial-stability risk manageable, which is not the same as saying every investor can exit on demand.
Moving from Treasuries to private credit therefore exchanges visible duration volatility for credit, valuation and liquidity exposure. That can be a deliberate allocation choice. It should not be recorded as free diversification.
The next stress test will identify the hedge
The most informative future evidence will come from the next slowdown, not another inflation surprise. If growth weakens, inflation expectations remain anchored and long Treasury yields fall while equities decline, government duration will demonstrate that its recession-insurance channel is intact. If yields remain high because term premium, fiscal supply or inflation fears dominate, the structural challenge will look stronger.
Evidence can also arrive inside alternative assets. Wider private-credit spreads, larger redemption queues or falling infrastructure earnings during a slowdown would reveal risks that appraisal smoothing can hide. Conversely, resilient cash flows and usable liquidity under stress would strengthen the case for a broader defensive toolkit.
The practical conclusion is not a universal allocation prescription. It is a measurement rule: judge each asset by the shock it is meant to absorb. Bonds remain useful for income, liquidity and some growth shocks. Inflation-sensitive assets address a different vulnerability. A robust portfolio makes those roles explicit rather than asking one traditional stock-bond correlation to carry every regime.