Rebuilding 60/40 portfolios with alternatives

Key Takeaways

• The macro environment that supported 60/40 stock-bond portfolios has shifted, with more frequent supply-driven shocks and higher, more uncertain inflation making diversification from bonds less reliable.
• At the same time, equity market concentration has increased, with secular themes such as artificial intelligence (AI) leaving portfolios more reliant on a narrower set of return drivers.
• Despite weaker diversification and increased concentration, dispersion within and across markets has expanded, creating opportunities for liquid alternatives to access differentiated and diversifying sources of return.

The 60/40 portfolio, where 60% is invested in stocks and 40% in bonds, has long served as a foundation for portfolio construction. While the exact asset mix is tailored to an investor’s risk tolerance, time horizon, and financial goals, the pairing of stocks and bonds has historically been considered a balanced approach, underpinned by bonds’ tendency to offset declines in equities and cushion losses during periods of market stress.

The 60/40 portfolio today

In recent years, however, the macroeconomic regime that supported this allocation framework has shifted. A more complex environment—characterized by higher inflation, policy uncertainty, and more frequent supply-driven disruptions—has challenged the traditional drivers of 60/40 performance. The chart below shows how this has translated into lower returns and higher volatility relative to the prior decade.

A key challenge for the 60/40 portfolio has been the weakening of the stock-bond relationship that has historically supported diversification. This reflects a broader shift in market structure from the post-GFC environment, when macroeconomic shocks were largely demand-driven. Today, the environment is shaped by persistent supply-side disruptions, including the pandemic and subsequent geopolitical events that have contributed to higher energy costs and broader price pressures.

The nature of these shocks matters for the role of bonds in portfolios. In demand-driven slowdowns, bond prices typically rise as yields fall to support economic growth, helping to cushion losses in risk assets. Supply-side disruptions can have the opposite effect, with bond prices falling and yields rising in response to price pressures, reducing their ability to provide diversification. With inflation remaining persistently above target, the scope for central banks to lower interest rates is greatly reduced, even as equity markets decline in response to these shocks. As a result, bonds have been less effective in providing diversification during periods of equity market stress.

While bonds have at times regained their diversifying characteristics in recent years, this relationship has become less reliable in a macro environment shaped by persistent supply constraints. Episodes of renewed inflation concerns have led to both asset classes declining in unison, with the Iran oil shock providing a recent example. March marked the second weakest month for 60/40 portfolios since the drawdowns of 2022, as markets initially reacted to the inflationary impulse by pricing out expectations for rate cuts and shifting toward a higher-for-longer rate outlook, with less immediate focus on longer-term growth risks that can emerge if price pressures begin to weigh on economic activity.

The chart below shows how the role of bonds as diversifiers has changed in the post-COVID period. Since 2020, bond market returns have been negative in 17 of the 19 months when equities declined by 2% or more, including most recently in March 2026.

Adding to these diversification challenges, the rise of AI has contributed to a highly concentrated equity market, with mega-cap leaders representing a historically large share of broad indices. The top 10 largest companies in the S&P 500 account for roughly 37% of total market capitalization today, compared to 29% in 2020 and 19% in 2010.¹ While market rotations and a broadening in performance leadership have reduced this from recent highs above 40%, concentration remains a defining feature of markets, leaving portfolios benchmarked to broad equity exposures increasingly reliant on a narrower set of return drivers.

Rebuilding the 60/40 portfolio with new return sources

With traditional 60/40 portfolios facing headwinds, the need for differentiated and complementary sources of return has grown. The traditional 60/40 framework is built on capturing directional market drivers. Whether constructed through broad index exposures or long-only stock and bond portfolios, performance is closely tied to the ups and downs of broad markets.

One way to diversify beyond directionality is by sourcing returns from the cross-section of markets, focusing on the relative differences that arise within and across markets. These differences are often referred to as dispersion, where higher levels reflect widening gaps in performance.

Strategies with the ability to invest both long and short, including liquid alternatives, can take advantage of this dispersion. By taking long positions in securities expected to outperform and short positions in those expected to underperform, these strategies seek to generate returns from differences in performance. This approach allows them to capture the spread between winners and losers, with returns driven by skill in forecasting relative outcomes rather than relying on securities to rise in absolute terms.

This distinct return profile is designed to have low correlation to traditional stock and bond allocations, making these strategies both complementary and diversifying within portfolios. By focusing on relative performance between long and short positions and emphasizing idiosyncratic, or asset-specific, sources of return while minimizing exposure to broader market movements, these strategies seek to isolate the underlying differences between securities regardless of market direction.

In addition, market-neutral strategies with a defensive return profile—emphasizing insights that tend to perform strongest during periods of market stress—can further support diversification and improve return consistency, particularly in down markets when it matters most.

Dispersion has increased in recent years, driven by structural changes in the post-COVID environment. Supply-side disruptions, higher input costs, and shifting global supply chains have widened the gap between winners and losers. At the company level, themes such as AI and a more challenging macro backdrop are driving greater separation in performance. At the macro level, divergent inflation and policy paths are contributing to a more uneven global environment, creating opportunities across countries and asset classes to capture these differences.

The ability to capture these cross-sectional opportunities introduces a distinct source of return that behaves differently from broad stock and bond markets, helping restore diversification and improve risk-adjusted return potential in portfolios.

Enhancing portfolio outcomes with liquid alternatives

A closer look at how liquid alternatives can influence portfolio outcomes is shown in the chart below, which presents a historical analysis comparing traditional stock-bond portfolios across different allocations (black line) with portfolios that include a 20% allocation to liquid alternatives (red line).

Over this period, incorporating liquid alternatives improved portfolio efficiency across this range of allocations. For example, at a similar level of risk to a traditional 60/40 portfolio, including a 20% allocation to liquid alternatives increased returns from 6.7% to approximately 9.2%. Conversely, at a similar level of return, volatility declined from 11.6% to approximately 9.3%.

More broadly, this highlights an important shift in portfolio construction. In an environment shaped by recurring supply-driven shocks, where diversification has become less reliable and returns more narrowly concentrated, integrating differentiated sources of return can expand the opportunity set and improve portfolio resilience.

Rather than replacing the traditional 60/40 framework, these strategies can enhance it by introducing new return drivers that are less dependent on market direction and better positioned to complement existing stock and bond exposures. In doing so, they can help restore diversification and improve the consistency of outcomes across a wider range of market environments.