Bonds vs Cash Equivalents
Bonds vs Cash Equivalents
For decades, bonds were the obvious choice for conservative portfolios. But the 2023–2024 era of 5% money market rates and inverted yield curves forced investors to reconsider: sometimes cash is a safer and higher-returning choice than bonds.
Key takeaways
- Money market funds and short-term treasuries now offer 4–5% yields, approaching or matching intermediate bond yields
- The 2023–2024 cash boom inverted the traditional equation: cash became less of a holding cost and more of a legitimate portfolio component
- Bonds and cash serve different roles—bonds are for diversification, cash is for psychological safety and optionality
- The yield curve's shape matters; when long-term rates are low relative to short-term, cash becomes more attractive
- Most investors need both, allocated to different goals
The historical context: why bonds beat cash before 2023
For the past three decades, cash paid almost nothing. In 2010, money market yields were 0.01%. In 2015, the Fed Funds rate was 0.25%, and money market funds returned negligible amounts. The entire rationale for holding bonds instead of cash was simple: bonds offered yield without the near-total loss of growth that cash represented.
A 10-year Treasury in 2010 yielded 3%. In 2020, it yielded 0.5%. Even in 2022, with the Fed rate at 0.75% and rising, money market funds were still earning only 1–2% while 10-year Treasuries yielded 3–4%. The choice was obvious: bonds, with their longer duration and (usually) higher yields, dominated cash as a portfolio holding.
This created a cultural bias. Robo-advisors, financial planners, and asset allocators defaulted to bonds for conservative portfolios. The idea of holding material amounts of cash (beyond a 3-month emergency fund) seemed like leaving money on the table.
Then the Fed raised rates aggressively in 2022–2023.
The 2023–2024 shift
By mid-2023, the Fed Funds rate had reached 5.25%–5.50%. Money market funds—which track the Fed Funds rate closely—started paying 5% or more. A Vanguard money market fund (VMFXX) offered 5.1% yield. BlackRock's iMoney Market Fund (MMMXX) offered 5.2%. These are not bond-equivalent funds; they are pure cash, fully liquid, with zero interest rate risk.
Simultaneously, the 10-year Treasury yield had settled around 4%–4.5%. For the first time in 30 years, cash was earning nearly as much as bonds, with vastly less risk. A 10-year Treasury still carried 2–3 years of duration risk (if rates rose, you'd lose principal). A money market fund carried zero duration risk.
The math was stark. If you believed rates would stay high (or rise further), buying a 10-year Treasury at 4.2% when you could get 5.1% from cash was leaving money on the table while taking more risk. Bond investors who had locked in 2% yields in 2021 were now underwater on unrealized losses. A $100k position in the Vanguard Total Bond Market Index (BND) that had been worth $100k in 2021 was worth roughly $91k in 2023 due to rising rates.
When does each win?
The choice between bonds and cash depends on three variables: the slope of the yield curve, the volatility regime, and your goal.
Yield curve slope: When short-term rates (cash) are close to or above long-term rates (bonds), cash wins on returns. The yield curve was inverted from mid-2022 through most of 2023—meaning the 2-year Treasury yielded more than the 10-year. In this regime, buying short-term cash instead of long-term bonds is the rational choice. You get similar returns (or better) with lower duration risk. By early 2024, the curve had begun to normalize, with 10-year Treasuries offering 4.1%–4.3% and money market funds still at 5.1%–5.3%, so the choice remained: cash for safety, bonds for optionality (if rates fall, bonds rally).
Volatility: Bonds provide return in exchange for duration risk—if rates rise unexpectedly, you lose principal. Cash provides return with zero duration risk. In low-volatility regimes (2017–2019), bonds won because the return premium over cash was large and rates were unlikely to spike. In high-volatility, high-rate regimes (2023–2024), the return premium disappeared and duration risk remained, so cash looked better.
Your goal: If you are buying a bond fund to hold for three years as a fixed anchor in your portfolio, cash might be the better choice. You get 5% yield, no surprises, and you can redeploy the principal in three years when your goal arrives. If you are building a 30-year retirement portfolio and you expect long-term rates to fall from current levels (back to 2–3%), bonds are the better choice because they appreciate when rates fall and offer better return than cash over decades.
The 2024 reversal
By late 2024, the Fed had cut rates from 5.25% to 4.25%–4.50% and was signaling further cuts. Money market funds dropped to 4.2%–4.4%. Meanwhile, 10-year Treasuries rose slightly in yield to 4.2%–4.5%, but bond prices had stabilized. The advantage of cash had eroded, and the long-term case for bonds re-emerged.
Most economists expect further rate cuts into 2025, pushing money market yields toward 3% while 10-year Treasuries might settle around 3.5%–4%. At that point, the yield curve would normalize again, and bonds would once more offer an attractive premium over cash. The 2023–2024 cash boom was a temporary anomaly driven by unusually high Fed Funds rates relative to long-term growth expectations.
Portfolio architecture: bonds and cash are not substitutes
The most sophisticated approach is to recognize that bonds and cash serve different roles in a portfolio. Bonds are part of your strategic allocation—they reduce equity volatility and provide diversification. Cash is part of your tactical cushion—it funds opportunities, handles emergencies, and provides psychological safety.
A well-designed portfolio might look like this:
- Equities: 50–70% (VTI, VXUS, or similar)
- Bonds: 20–40% (BND, AGG, or intermediate Treasury ladder)
- Cash: 5–10% (money market fund, short-term Treasury, or savings account)
During normal times (bull markets, normalized yield curve), you rebalance by trimming equities and deploying into bonds or cash. During crashes (2008, 2020), you use cash to seize opportunities without taking duration risk. When the yield curve inverts and cash offers 5% (like 2023), you might shift a portion of your bond allocation to cash for the duration of that regime, then rebalance back when the curve normalizes.
The error many investors make is treating cash and bonds as perfect substitutes. They are not. The best approach is to hold both, sized to different time horizons and goals.
Practical implementation in 2024–2025
If you are building a new portfolio today and you expect rates to decline, a mix of 40% intermediate bonds (BND, VBTLX, or 5–7 year Treasury ladder) and 10% cash (VMFXX, SPAXX, or 6-month Treasury bills) makes sense. You capture the return of bonds (4.2%–4.5% yield plus potential capital appreciation if rates fall) while maintaining a cash cushion (currently 4.3%–4.4% yield).
If you already own bonds bought at lower yields (2–3%), do not sell them to chase current cash rates. You have locked-in return, and when rates fall (as most expect), your bonds will appreciate. New money should go to cash at current rates, then rotate into bonds if rates climb further. The portfolio of a practitioner rebalances opportunistically between these buckets rather than maintaining a static allocation.
Decision tree: bonds or cash?
Next
Now that you understand the choice between bonds and cash, and how rebalancing uses bonds as fuel, the question arises: what happens when bonds fail to diversify? The next article tackles the rare but catastrophic moments when stocks and bonds fall together, destroying the classic diversification narrative.