90/10 vs. 60/40: Is the WSJ Right That You Own Too Many Bonds?

Robert Pozen, a former president of Fidelity Investments and senior lecturer at MIT Sloan, argued in a May 2026 Wall Street Journal opinion piece that many affluent investors hold too much in bonds. His alternative: 90% in a low-cost stock index fund, 10% in a money-market fund, rebalanced annually. No adviser needed.

The article drew a pointed response from portfolio researcher Ptuomov, who asked a different question: starting with 90/10 stocks and cash, would the portfolio improve if you added long-duration Treasury futures on top? That question reframes the debate from “stocks versus bonds” to “concentrated equity versus capital-efficient diversification.”

Both sides have merit, and both overstate their case in certain ways.

A Quick Correction: Money-Market Fund, Not T-Bills

Pozen proposes 90% stocks and 10% in a money-market fund, not 10% in Treasury bills. A money-market fund may hold T-bills among other short-term instruments (commercial paper, agency debt, repurchase agreements), but it is not identical to directly owning T-bills. For the historical backtests in this guide, we use 3-month T-bill returns as the closest available proxy, which is standard practice in academic research.

Pozen identifies two target groups for 90/10: households with at least $1 million in investable assets (excluding homes), and households with more than $100,000 whose noninvestment income covers their cost of living.

Three Portfolios, Three Questions

The debate is easier to follow if you distinguish three separate portfolios rather than treating it as a binary choice between stocks and bonds.

Pozen changes the funded allocation: sell bonds, buy stocks. Ptuomov changes the total risk exposure: keep the stocks, keep the cash, and layer on additional bond duration through derivatives. A 90/10 portfolio has 100% funded exposure. A 90/10 portfolio plus 15% Ultra T-Bond futures has roughly 115% gross market exposure.

Where 90/10 Is Strongest

Investors with high risk capacity may reasonably hold more equity

Over every 20-, 30-, 40-, 50-, and 60-year period ending with 2025, U.S. stocks have outperformed 10-year Treasury bonds by a wide margin. Pozen’s ten-year illustration is reproducible: $100,000 invested from 2016 through 2025 in a 90/10 portfolio (S&P 500 / T-bills, annual rebalancing) grew to approximately $356,000, compared to approximately $243,000 in a 60/40 portfolio (S&P 500 / 10-year Treasury bonds) Damodaran, NYU Stern.

For a household with stable outside income, substantial liquidity, a genuinely long horizon, and a demonstrated ability to remain invested during severe losses, the key risk may not be short-term portfolio volatility. It may be failing to accumulate enough real wealth over decades, especially when the portfolio is intended partly for bequests, philanthropy, or late-life flexibility.

Cash can be more useful than bonds for near-term spending uncertainty

A money-market reserve is not designed to offset every equity decline. Its primary function is liquidity: funds available quickly and without principal risk to cover unexpected needs. For a household whose lifestyle is already supported by salary, pension, Social Security, or rental income, a modest cash reserve may be enough to avoid forced stock sales.

Simplicity has behavioral value

A two-fund portfolio is easy to understand, rebalance, and maintain. Many investors do more damage through performance chasing, unnecessary complexity, expensive products, or poor timing than through selecting a reasonable but imperfect strategic allocation.

Recent life-cycle research supports higher equity for some investors

Anarkulova, Cederburg, and O’Doherty (2023) examine life-cycle portfolio choice using international market history and find that portfolios heavily invested in globally diversified equities can outperform conventional stock-bond strategies in retirement outcomes under their model assumptions SSRN. Their optimal allocation is not Pozen’s U.S.-centric 90/10; it is closer to a globally diversified equity portfolio with roughly one-third domestic and two-thirds international stocks, and little fixed income.

Where 90/10 Goes Too Far

A dollar threshold does not determine risk capacity

Two households with $1 million in investable assets can face very different risks:

Zvi Bodie’s life-cycle investing research makes the broader point: age and wealth alone do not determine the correct stock allocation. Human capital, spending needs, labor-income risk, and the correlation between employment income and stock-market risk all matter Boston Fed.

U.S. stock outperformance is evidence, not a forward-looking law

Pozen’s return comparisons depend on the realized success of the S&P 500, which has had extraordinary long-run outcomes, particularly over periods ending recently. A diversified investor should not read past U.S. performance as proof that domestic equities will dominate every future multi-decade period. For more on why global equity diversification matters, see the Summitward guide on the case for global diversification.

Bonds serve purposes that cash does not fully replace

A 10% money-market position offers stability and liquidity but zero duration exposure. High-quality intermediate or long Treasuries can appreciate during recessionary or deflationary shocks when stocks fall. In 2008, the S&P 500 returned -36.55% while 10-year Treasuries returned +20.10%. In the 2000-2002 dot-com bust (S&P 500 down a cumulative 37.6%), 10-year Treasuries returned +16.66%, +5.57%, and +15.12% respectively Damodaran, NYU Stern.

That diversification is conditional, not guaranteed. In 2022, the S&P 500 returned -18.04% and 10-year Treasuries returned -17.83%. Stock-bond correlation varies across inflation regimes. Campbell, Sunderam, and Viceira document that Treasury bonds were strong equity hedges during much of the early 2000s but can fall alongside stocks when inflation uncertainty rises.

The correct conclusion is that long-duration bonds are conditional diversifiers, not guaranteed crash insurance. One adverse regime does not eliminate their diversification value in other regimes.

A Number Worth Checking

Pozen’s ten-year comparison is reproducible and checks out. His forty-year comparison deserves closer examination.

Pozen reports that $100,000 invested for 40 years would have grown to approximately $5.8 million in 90/10 and $2.5 million in “60/40 stocks/bonds.” Using Damodaran’s NYU annual return series from 1986 through 2025 with annual rebalancing:

The 90/10 result matches Pozen’s reported figure. But his reported ~$2.5 million for “60/40 stocks/bonds” is much closer to a portfolio holding 40% T-bills, not 40% 10-year Treasury bonds. With 40% in 10-year Treasuries, the forty-year ending value is approximately $3.69 million, not $2.5 million.

The distinction matters because 10-year Treasury bonds earned substantially higher returns than T-bills over most of that period. The article compares an aggressive equity portfolio against what may be a weaker baseline than readers assume. Without seeing the author’s exact methodology, readers should treat the forty-year comparison cautiously.

You can test this yourself in the backtester below. Set the starting year to 1986 and the horizon to 40 years, then toggle between 60/40 Bonds and 90/10 Cash.

The Sophisticated Critique: Treasury Futures

Ptuomov’s question reframes the entire debate. He does not argue that bonds are better than stocks. He asks whether an aggressive investor can keep 90% stocks, maintain cash for liquidity and collateral, and add long-duration Treasury exposure through futures without selling any equity.

CME’s Ultra U.S. Treasury Bond futures reference bonds with at least 25 years remaining to maturity, making them far more sensitive to long-term rate changes than T-bills or intermediate bonds CME Group.

The logic is consistent with Cliff Asness’s argument in “Why Not 100% Equities”: investors should separate two decisions: (1) identifying the best risk-adjusted portfolio and (2) choosing how much total risk to take. Rather than holding 100% equities, an investor with high risk tolerance could lever a diversified portfolio to reach the desired expected return AQR.

Pozen asks whether investors should hold more stocks. Ptuomov asks whether investors can hold more total compensated risk while still preserving diversification. That is a more sophisticated portfolio-construction question.

Why the Overlay Is Not a DIY Solution

The portfolio becomes leveraged

A 90/10 portfolio plus 15% bond futures has more market exposure than the investor’s net capital. Futures are marked to market daily, so losses can require additional cash collateral at exactly the wrong time. The National Futures Association cautions that futures should be traded only with risk capital beyond funds needed for necessities, emergencies, and long-term goals.

Ultra-long Treasuries can lose substantially

Long-duration futures add major interest-rate sensitivity. If yields rise because of inflation, fiscal concerns, or rising real rates, the futures position can lose money even while equities are also declining. An investor who viewed the overlay as “extra safety” could be surprised in a repeat of 2022-style conditions.

“15% of futures” is not the correct risk measure

A 15% notional position in very long-duration Treasury futures carries far more interest-rate sensitivity than a 15% allocation to intermediate bonds. Proper sizing requires duration risk (DV01), stress-tested loss scenarios, margin and collateral analysis, and clear rebalancing rules.

The best research does not endorse this as a default

Anarkulova, Cederburg, and O’Doherty test the Asness-style leverage critique explicitly. In their model, bonds enter the optimal portfolio only under the lowest derivative-implied financing-cost assumption, and even then the solution involves extreme leverage (borrowing at a 100% cap) while holding approximately 15% bonds alongside leveraged equities. The authors also caution that households face practical barriers to derivative use and active management SSRN.

For readers interested in the mechanics of leveraged diversification, see the Summitward guides on return stacking and portable alpha and managed futures.

Try It: Portfolio Allocation Backtester

The backtester below uses annual S&P 500, 3-month T-bill, and 10-year U.S. Treasury bond total returns from 1928 through 2025 (Damodaran, NYU Stern). All portfolios rebalance annually to target weights. Toggle allocations on and off to compare them across different historical periods.

To reproduce Pozen’s ten-year comparison: set starting year to 2016 and horizon to 10 years with the default $100,000 portfolio, then enable both 90/10 Cash and 60/40 Bonds.

Who Each Portfolio Fits

A high-equity portfolio (90/10 or similar) may fit investors who:

• Have a genuinely long investment horizon (20+ years before they need material withdrawals).
• Have stable income or other resources covering foreseeable spending.
• Maintain a separate emergency reserve outside the portfolio.
• Use diversified, low-cost equity exposure rather than concentrated bets.
• Have demonstrated an ability to remain invested through very large losses (not merely stated it).

A more balanced portfolio (60/40 or similar) may fit investors who:

• Are withdrawing materially from their portfolio in retirement or semi-retirement.
• Have upcoming tuition, housing, caregiving, or major spending needs.
• Would be unable or unwilling to tolerate a 40-50% equity decline without selling.
• Have employment income, RSUs, or business ownership already exposed to equity-market risk.
• Value stability and rebalancing capacity more than maximum expected ending wealth.

A Treasury-futures overlay may fit only investors who:

• Already understand futures, collateral, margin, duration, and rebalancing.
• Can size exposure by DV01 and stress-tested portfolio loss rather than notional percentage.
• Can maintain substantial liquid collateral without jeopardizing emergency reserves.
• Understand that long Treasuries may lose money at the same time as stocks.
• Have a written investment policy explaining why leverage is being used and when it will be reduced.

For most DIY investors, the complexity and execution risk of a futures overlay outweigh the theoretical improvement. For a deeper look at how different allocations affect early retirement, see the Summitward guide on safe withdrawal rates.

Frequently Asked Questions

Is 90/10 really better than 60/40?

Over most long historical periods using U.S. data, a 90/10 stock/cash portfolio has produced higher ending wealth than 60/40 stock/bond. The tradeoff is substantially larger drawdowns and no duration diversification during growth-led recessions. “Better” depends on whether the investor can actually tolerate and remain invested through those drawdowns. For a deeper look at how different allocations compare, see the Summitward guide on the asset allocation debate.

Does this mean I should sell all my bonds?

No. The article applies to investors with high risk capacity, long horizons, and little need to draw from their portfolio. If you are spending from your portfolio, funding near-term goals, or unable to tolerate very large equity losses, bonds or other stable assets serve a real purpose. See the Summitward guide on asset-liability matching for when bonds are the right tool.

What about using a globally diversified stock portfolio instead of the S&P 500?

Pozen’s article uses the S&P 500. The strongest version of the high-equity argument, from Anarkulova, Cederburg, and O’Doherty, uses a globally diversified equity portfolio with roughly one-third domestic and two-thirds international. U.S. concentration risk is real: the S&P 500’s recent dominance is not guaranteed to persist. See the Summitward guide on global diversification.

Should I add Treasury futures to my portfolio?

Probably not, unless you already understand futures mechanics, duration risk, margin management, and portfolio-level stress testing. The intellectual case for leveraged diversification is sound, but the implementation carries risks that most DIY investors should not take on. A simpler path to a diversified portfolio is to hold appropriate amounts of stocks, bonds, and cash matched to your actual spending needs and risk capacity.

What went wrong with bonds in 2022?

In 2022, the S&P 500 returned -18.04% and 10-year Treasuries returned -17.83%. Both fell because of rapidly rising interest rates driven by high inflation. This was a breakdown in the typical negative stock-bond correlation that investors rely on for diversification. Stock-bond correlation varies across inflation regimes: bonds have been strong equity hedges in some environments (2008, early 2000s) and weak or negative hedges in others (2022, 1970s). One bad year does not eliminate the diversification value of bonds across other market regimes.

Related Guides

• 60/40, Target-Date Funds, or 100% Stocks Forever? compares the philosophical cases for each allocation approach.
• Stocks Usually Win. “Usually” Is Not a Financial Plan. covers 220 years of stock-vs-bond evidence and when “usually” is not enough.
• Lifecycle Asset Allocation explains why human capital, age, and spending needs shape the right stock-bond mix.
• Sequence of Returns Risk shows why the order of returns matters more than the average, especially for retirees.
• Safe Withdrawal Rate explores how different allocations affect retirement spending sustainability.
• Asset-Liability Matching covers when bonds serve a specific purpose tied to real spending needs.
• Return Stacking and Portable Alpha explains the mechanics of leveraged diversification and capital-efficient portfolios.
• The Case for Global Diversification covers why U.S.-only equity exposure is a concentration bet.

Key Takeaways

• 60/40 is not a universal default. Investors with long horizons, strong external income, and very high risk capacity may rationally hold more equity than conventional advice suggests.
• 90/10 is not universally “far better.” Pozen’s argument is strongest for investors who do not need to draw from their portfolio and weakest for anyone whose spending, behavior, or liabilities require stability.
• The forty-year comparison deserves scrutiny. Pozen’s reported 60/40 ending value more closely matches a portfolio holding T-bills than 10-year Treasury bonds. The distinction changes the magnitude of 90/10’s advantage.
• The futures critique is intellectually valid but not a DIY recommendation. Leveraged diversification through Treasury futures is a better portfolio-construction question than “stocks versus bonds.” It is also an advanced strategy with real operational and behavioral risks.
• Allocation should follow a financial plan, not a headline. Define what the portfolio must fund, how much loss you can actually withstand, and whether diversification serves a real purpose. Then choose the allocation.

Sources

1. Robert C. Pozen, “You’re Probably Overinvested in Bonds,” Wall Street Journal Opinion, May 21, 2026. wsj.com
2. Aswath Damodaran, NYU Stern, Historical Returns on Stocks, Bonds and Bills (1928–2025). pages.stern.nyu.edu
3. Anarkulova, A., Cederburg, S., and O’Doherty, M., “Beyond the Status Quo: A Critical Assessment of Lifecycle Investment Advice” (2023). SSRN
4. Cliff Asness, “Why Not 100% Equities,” AQR Capital Management. aqr.com
5. CME Group, Ultra U.S. Treasury Bond Futures and Options. cmegroup.com
6. Zvi Bodie, “The Theory of Life-Cycle Saving and Investing,” Federal Reserve Bank of Boston. bostonfed.org
7. National Futures Association, Investor Best Practices. nfa.futures.org
8. IRS, Publication 550: Investment Income and Expenses (2025). irs.gov