Chapter 4
Building Blocks of Long-Run Returns
Every long-only investment can be decomposed into the riskless cash return (reward for time) plus various risk premia. Ilmanen presents a pyramid framework showing how portfolio returns comprise different components, from cash returns at the base through various risk premia to alpha at the peak.
Cash returns deserve special focus as their abnormally low levels drive today's investment challenges. While the historical "normal" US cash rate was around 4% (2-3% inflation plus 1-2% real rate), recent years have seen near-zero or even negative rates globally. The recent period of persistently negative real rates since 2008 contrasts sharply with peak values of 3-4% in the 1980s and 2000.
The equity risk premium stands as the most important risk premium for most investors. Public equities dominate many portfolios, and their premium influences many assets beyond public stocks, including high-yield bonds and private equity. According to Dimson-Marsh-Staunton data covering 1900-2020, global equities delivered 5.3% real return, 4.4% premium over bills, and 3.1% premium over bonds. US equities outperformed other countries (6.6% versus 4.5% real return), primarily due to faster real dividend growth.
However, historical average returns almost certainly overstate future prospects. Looking forward, mid-2021 estimates point to about 3.2% real return on US equities (1.7% income, 1.5% growth), or 5.5% nominal return with 2.3% inflation. Non-US markets offer higher expected returns due to lower valuations.
The bond risk premium or term premium is the excess return of long-term government bonds over cash. Over the century 1920-2020, bonds delivered a 1.8% annual premium over cash. The 10-year Treasury yield can be broken down into three components: expected average inflation rates, expected average real short rates over the next decade, and the required bond risk premium. All three components contributed to the decline in Treasury yields over time, and by 2020, all were near historical lows.
Chapter 5
The Illusion of Illiquidity Premia
Many investors believe strongly in illiquidity premia - the extra return earned for accepting lockups and trading limitations. However, careful empirical analysis reveals surprisingly modest returns for the illiquidity risks taken. Private assets like real estate, private equity, and infrastructure are often marketed as offering superior returns in exchange for illiquidity, but the evidence is less compelling than commonly believed.
Contrary to expectations, more liquid REITs outperformed illiquid NCREIF investments (7% versus 4% compound return over cash) during the 43-year period from 1978-2020. Even when adjusted for differences in leverage and sector composition, REITs still showed mildly higher returns.
The surprising scarcity of illiquidity premia can be explained by private assets' lack of mark-to-market pricing, which artificially lowers measured risk and flatters diversification potential. While investors theoretically should demand 3-5% excess return for decade-long capital lockups, our collective preference for smooth returns likely offsets much of this fair premium. As Keynes noted in 1938, the absence of visible price fluctuations doesn't make investments safer.
Real estate investors should recognize that recent decades' rising prices benefited from the one-off boost of falling real yields. Attribution analysis shows that starting from today's 4% gross yield (2.7% net) and assuming zero real growth and valuation changes, the expected real return is just 2.7% - potentially lower if real income growth remains negative or valuations mean-revert.
Chapter 6
Style Premia: The Overlooked Opportunity
Style premia represent systematic dynamic long/short strategies with expected positive rewards, supported by compelling long-run evidence across multiple asset classes. Four major style categories - value, momentum, carry, and defensive - have historically generated positive returns in-sample and out-of-sample, across various asset classes, and using multiple specifications.
Value investing applies contrarian principles across security selection, asset allocation, and market timing. Dating back to Graham-Dodd's work in the 1930s, value investing has centuries of success despite notorious periods of failure. Value strategies typically involve comparing current market prices with fundamental anchors to identify cheap or expensive assets. While value strategies performed dismally between 2018-2020, the resulting extreme valuation gap created a compelling opportunity, with value beginning to recover in late 2020.
Momentum strategies buy recent winners and sell recent losers, applied either as directional trend following on individual assets or as cross-sectional momentum portfolios based on relative performance. While contrarian strategies buy weakness, momentum buys strength - the key is that they work at different time horizons. Assets exhibit trending tendencies up to one year but mean-revert at multiyear horizons. The negative correlation between value and momentum strategies (often near -0.5) makes them excellent complements in a portfolio.
Carry strategies earn positive income over time, typically by buying high-yielding assets against selling low-yielding ones. Though positive carry doesn't guarantee positive returns, it empirically predicts them, with varying effectiveness across asset classes. Carry strategies are notorious for asymmetric outcomes ("going up the stairs, down the elevator") but their left-tail risk can be diversified away in a broad carry portfolio since crashes tend to be asset-class specific.
Defensive strategies exploit the empirical fact that "boring" assets have earned better risk-adjusted returns than speculative ones across most asset classes. Within stock markets, defensive stocks have earned at least as high long-term returns as riskier stocks, contradicting the notion of a positive risk-reward trade-off. This phenomenon can be explained by leverage constraints (investors cannot fully exploit boring stocks' superior Sharpe ratios by levering them up) and lottery preferences (many investors prefer high-risk stocks for their embedded leverage and lottery-like payoffs).
Chapter 7
Portfolio Construction in a Low Return World
Portfolio construction involves balancing risk and reward through constrained mean-variance optimization (MVO). The key insight in unconstrained MVO is valuing high Sharpe ratios and good diversifiers, trading off these features against constraints on leverage and liquidity.
Diversification offers tremendous benefits that are frequently underutilized, with most investors maintaining home-biased portfolios dominated by equity risk. Few take full advantage of multiple rewarded factors, which would require shorting and leverage but could potentially boost Sharpe ratios fourfold. Risk parity portfolios with equal risk across uncorrelated assets can achieve Sharpe ratios 1.7 times higher than individual asset classes, though leverage is needed to match 60/40 returns.
Alternative risk premia diversification offers the greatest benefits, particularly with lowly-correlated long/short strategies. Combining four styles across four asset classes can potentially quadruple Sharpe ratios from 0.2 to 0.8. Empirical evidence from a century of data confirms these benefits - single-style strategies averaged 0.4 Sharpe ratios, multi-style composites reached 0.8, and the all-in composite achieved 1.5.
However, aggressive diversification has downsides beyond high leverage - diversified portfolios often lack conventionality and simple narratives that investors find comforting. These very limitations may explain why the high Sharpe ratios of diversified portfolios have persisted for decades. In practice, most investors talk diversification but walk concentration, with portfolios dominated by equity market risk.
Chapter 8
Risk Management: Survival First
Risk management differs fundamentally from risk minimization - successful investors must deliberately embrace certain risks while protecting against those that could threaten survival or derail long-term objectives. Ilmanen outlines three classic risk management techniques that form the foundation of institutional portfolio management: diversification (spreading allocations across multiple assets with low correlations), hedging (taking offsetting positions to eliminate specific unwanted risks), and insurance (paying upfront costs to limit downside exposure).
The implementation of these techniques requires careful consideration of costs and tradeoffs. Diversification, while powerful, can become less effective during market stress when correlations spike. Hedging through futures or forwards may be cheaper than options but requires active management. Insurance through put options provides reliable protection but at a significant cost that erodes long-term returns.
In his notable debate with Nassim Taleb about tail risk management, Ilmanen presents evidence that put options consistently act as expensive insurance rather than cheap hedges. Historical data shows that put buying strategies generate negative long-run returns due to the persistent volatility risk premium. In contrast, trend-following strategies have delivered positive long-term returns while still providing valuable tail risk protection. This protection proves effective because most equity market crashes develop gradually enough for trend-followers to adjust their positions, with examples including the 2008 financial crisis and 2020 COVID crash.
Beyond traditional volatility measures, sophisticated investors must consider multiple interconnected risk dimensions. These include multi-factor exposures (sensitivity to interest rates, credit spreads, liquidity conditions, and volatility regimes), investor-specific preferences (asymmetric aversion to losses, requirements for liquid assets), operational risks (counterparty, systems, human error), and fundamentally unmeasurable Knightian uncertainty where probability distributions cannot be known.
Institutional investors face additional complexity in balancing multiple risk objectives. They must determine optimal trade-offs between absolute portfolio risk (total portfolio volatility), active risk versus benchmarks (tracking error), surplus risk (assets versus liabilities), and maverick risk (deviating too far from peer portfolios). The appropriate balance depends on factors like funding status, time horizon, and governance structure.
Effective risk management requires regular stress testing of portfolios against both historical scenarios and hypothetical events. This helps identify potential vulnerabilities and ensures survival during severe market dislocations while maintaining the ability to generate required returns over full market cycles.
Chapter 9
The ESG Revolution and Its Impact
ESG (Environmental, Social, and Governance) investing has become the past decade's biggest game-changer in institutional investing practices and corporate behavior. By 2020, over 3000 institutions with collective assets exceeding $100 trillion had signed the United Nations Principles for Responsible Investment, representing a seismic shift in how capital is allocated globally. Major asset managers like BlackRock, Vanguard, and State Street have made ESG integration central to their investment processes.
The ESG investing landscape encompasses multiple sophisticated approaches. Responsible asset selection has evolved from simple negative screening (excluding "sin stocks" like tobacco or weapons) to positive screening (actively seeking companies with strong ESG practices) and comprehensive ESG integration into fundamental analysis. This integration includes analyzing climate risk exposure, labor practices, supply chain sustainability, board diversity, and executive compensation structures. Responsible ownership has also matured, with investors expressing opinions through proxy voting on ESG issues and direct corporate engagement through shareholder proposals and private dialogue with management teams.
The impact of ESG investing on financial performance remains actively debated both theoretically and empirically. ESG proponents argue for a win-win scenario where virtuous investing doesn't sacrifice returns, pointing to companies like Tesla, rsted, and Unilever as examples of strong ESG performers delivering market-beating returns. They contend that companies with strong ESG practices are better positioned to navigate future risks and capitalize on opportunities in the transition to a sustainable economy.
Traditional finance theory suggests that any investment constraint, including ESG filters, should mathematically reduce the opportunity set and potentially harm returns. However, these perspectives can be reconciled by considering the transition timeline and market efficiency dynamics. During early stages of ESG adoption, identifying mispriced ESG risks and opportunities can potentially generate alpha. As markets mature and ESG factors become fully priced, returns may normalize.
Empirically, governance signals like board independence, shareholder rights, and accounting quality have consistently shown positive correlation with performance across multiple studies and time periods. Environmental and social impacts show mixed results, with some studies finding positive effects in specific sectors or time periods, while others show neutral or negative impacts. Regional differences are also significant, with European markets generally showing stronger ESG-performance relationships than other regions.
The rise of standardized ESG reporting frameworks, improved data quality, and sophisticated analytics tools continues to reshape how investors evaluate and integrate ESG factors into their investment processes. This evolution suggests that ESG considerations will likely become increasingly embedded in mainstream investment analysis rather than remaining a separate specialty approach.
Chapter 10
The Limits of Tactical Timing
Tactical market timing strategies often present beautifully in backtests and historical analyses but consistently fall short when implemented in real-world conditions. This is particularly evident with contrarian timing approaches using the Shiller CAPE (cyclically adjusted P/E ratio) for the S&P 500. While historical charts showing entry and exit points based on CAPE valuations appear compelling, these strategies have repeatedly disappointed investors in live trading environments. The data reveals a peculiar pattern: market timing strategies show mild outperformance over very long periods spanning 120 years, yet fail to deliver meaningful advantages during any individual investor's typical investment horizon of 30-40 years.
Contrarian timing signals face several significant challenges that limit their effectiveness. First, they often trigger "too early" - identifying overvaluation or undervaluation long before markets actually reverse. This early positioning can lead to substantial opportunity costs and psychological strain as markets continue moving against the position. For instance, investors who went defensive based on high CAPE readings in 1996 missed out on several years of strong returns before the eventual dot-com crash.
The second major challenge is the constant battle against both short-term momentum effects and long-term structural market changes. Markets can remain "overvalued" or "undervalued" far longer than most investors can maintain their contrarian positions. Additionally, structural changes in the market, such as the shift toward technology companies, changes in accounting standards, and evolving business models, can render historical valuation metrics less relevant for current market conditions.
When examining the empirical evidence, the improvements from timing strategies are surprisingly modest. While diversification across long/short style premia can achieve a doubling of the Sharpe ratio, and further diversification across multiple asset classes can nearly double it again, even the most successful out-of-sample style timing strategies only managed to improve the strategic long-run Sharpe ratio by less than 10%. This modest improvement hardly justifies the additional complexity, trading costs, and psychological challenges of implementing timing strategies.
The research also shows that timing signals tend to be too coarse for effective market timing. Markets rarely follow the clean, predictable patterns that historical analyses might suggest. Instead, they respond to a complex web of factors including monetary policy, geopolitical events, technological disruption, and changing investor behavior patterns - making precise timing based on any single metric or set of metrics extremely challenging.
Chapter 11
Avoiding Bad Habits in a Low Return World
Successful investing requires both good investments and good investors who can resist bad habits while cultivating good practices. Multiyear return chasing - buying winners and selling laggards across asset classes, strategies, stocks, or funds - stems from our deep behavioral tendency to imitate and extrapolate. While momentum works over multi-month horizons, markets exhibit mean reversion at multiyear horizons, making investor flows often poorly timed.
Goyal-Wahal's analysis of pension plans' manager hiring/firing decisions found that fired managers later outperformed their replacements. Stock returns show one-year momentum but five-year reversals - yet investors "act like momentum investors at reversal horizons," often abandoning strategies after 3-5 years of underperformance, just when higher returns might follow.
Other bad habits include impatience (leading to insufficient retirement savings), overextrapolation, herding, and overconfidence. Good practices include cultivating discipline, patience, and probabilistic thinking. As Morgan Housel puts it: "Save like a pessimist, invest like an optimist," emphasizing the importance of saving more in a low-return world while taking necessary risks.
Chapter 12
Finding Serenity in the Low Return Reality
The central dilemma facing investors in a low-return environment is whether to take more risk to meet return goals or reduce risk because expected returns are historically low. While many have chosen to increase risk, this path requires "open eyes" since investments have higher valuations and may be more vulnerable to corrections. Conversely, moving to cash is equally challenging with negative real rates.
The most justifiable approach may be maintaining a broadly similar portfolio as in normal times - sticking with long-term strategies while accepting lower returns, reducing waste, and investing efficiently. Having "borrowed returns from the future through multi-decade windfall gains," investors face a future of low returns that may materialize either as "slow pain" (persistent low income) or "fast pain" (repricing toward lower valuations and higher prospective returns).
Good long-term investing principles are timeless but matter more in challenging market environments: thoughtfully selecting return sources based on realistic investment beliefs; appropriately sizing risks based on risk-adjusted expected excess returns; investing strategically and patiently with minimal tactical timing; diversifying boldly with robust portfolios; executing cost-effectively; and governing well.
The author advocates for stable confidence rather than excessive humility, noting that investment outcomes depend on both luck and skill, with luck often dominating short-term results. Referencing the Serenity Prayer, he reminds investors to control the process while recognizing luck's role in outcomes. A serene mindset helps investors become more patient and consistent - essential qualities when a strategy is only good if you can stick with it.
