Enhancing Global Equity Returns: Trend-Following and Tail Risk Hedging Overlays
A 2025 study finds that overlaying trend-following and tail risk hedging on a global equity portfolio raised CAGR from 8.06% to 11.02% while cutting max drawdown from -34.3% to -19.1%.
- The Portable Alpha portfolio achieved a CAGR of 11.02% compared to 8.06% for the global equity index (ACWI) over the test period.
- Maximum drawdown was reduced from -34.3% in the index to -19.1% in the overlaid portfolio.
- The Sharpe ratio improved significantly from 0.37 (index) to 0.66 (overlaid portfolio).
- Portfolio volatility decreased from 15.57% to 13.23% despite the addition of overlay strategies.
- Negative skewness, a measure of crash risk common in equity portfolios, was almost eliminated.
Global developed market equities (MSCI World or ACWI) are the standard growth engine for most portfolios, but they come with a steep price: drawdowns of 30-50% during major crises. Most traditional risk management approaches involves selling equities to buy bonds or cash, which reduces drawdown but also reduces long-term returns. The Holy Grail of portfolio construction is a method that reduces risk without sacrificing return.
A 2025 paper by Bruno Schwalbach and Christo Auret, published in the Investment Analysts Journal (Vol. 54, No. 3), proposes a solution using a "Portable Alpha" framework. Instead of selling equities, the strategy maintains 100% exposure to global stocks and overlays two distinct signals on top: trend-following and tail risk hedging. The results are compelling: the combined portfolio significantly outperformed the passive index while cutting drawdowns nearly in half.
Methodology: Stacking, Not Switching
The paper constructs a Portable Alpha portfolio with three components:
- Beta (100%): Passive exposure to global equities (proxied by the MSCI ACWI All Country World Index). This ensures the portfolio captures the long-term equity risk premium.
- Alpha Component 1: Trend Following. This overlay is designed to profit from sustained market moves, both up and down. In the context of this paper, it serves as a slow-moving hedge during prolonged bear markets (like 2000-2002 or 2008) while adding returns during strong trends.
- Alpha Component 2: Tail Risk Hedging. This overlay is designed to profit from sudden, sharp market crashes (like March 2020). Unlike trend following, which takes time to react, tail hedging is positioned to capture explosive volatility spikes immediately.
The key innovation is that these components are not mutually exclusive. The portfolio does not switch between them; it stacks them. By using capital-efficient instruments (like futures or swaps) for the overlays, the investor can maintain full equity exposure while simultaneously holding the hedging strategies. This contrasts with traditional "risk-off" moves that require selling the core asset.
The Results
Comparing the Portable Alpha portfolio to the passive Global Equity index (ACWI) over the study period:
- Annual Return (CAGR): The Portable Alpha portfolio returned 11.02% annually, compared to 8.06% for the ACWI. That is an excess return of nearly 300 basis points per year largely derived from risk management.
- Maximum Drawdown: The passive equity index suffered a maximum drawdown of -34.3%. The Portable Alpha portfolio limited this to -19.1%.
- Sharpe Ratio: The risk-adjusted return nearly doubled, rising from 0.37 for the ACWI to 0.66 for the Portable Alpha portfolio.
- Volatility: Despite adding leverage to hold the overlays, the overall portfolio volatility dropped from 15.57% to 13.23%.
Perhaps most importantly for long-term compounding, the negative skewness typically causing "crash risk" in equity portfolios was "almost eliminated." The overlays effectively filled in the deep valleys of the equity curve.
Why Two Hedges?
The paper argues that trend-following and tail hedging are complementary, not redundant. Trend following works well in slow, grinding bear markets where prices trend lower over months. However, it can be too slow to react to a sudden shock like the COVID-19 crash in early 2020. Tail risk hedging covers that specific gap. Conversely, tail hedging is expensive to carry during calm bull markets (the "negative carry" problem), but trend following can generate positive returns during those same periods to offset the cost. Combining them creates a more robust all-weather defense than either strategy alone.
Relevance to Active Strategies
The concept of overlaying uncorrelated positive-expectancy strategies on top of a core beta exposure is central to modern portfolio design. While the paper uses customized derivatives for its overlays, the principle can be applied using separate systematic strategies.
The RealTest ETF Rotate Monthly Rebalance Strategy uses momentum (a form of trend following) to rotate exposure, which historically reduces drawdowns relative to buy-and-hold.
Limitations
The primary barrier to implementing this exact strategy for individuals is leverage management. "Portable Alpha" requires using derivatives (futures) to gain the beta exposure so that cash remains free to collateralize the alpha strategies, or vice versa. This introduces margin risk and roll costs that valid backtests must account for.
Additionally, tail risk hedging is notoriously difficult to calibrate. Buying puts is a guaranteed cost that bleeds performance during bull markets. The paper achieves a net benefit, but in practice, the timing and sizing of the hedge are critical variable. A poorly constructed hedge can drag performance down more than it saves during a crash.
Citation: Schwalbach, B. and Auret, C. (2025). Enhancing global equity returns with trend-following and tail risk hedging overlays. Investment Analysts Journal, 54(3), 364–386. https://www.tandfonline.com/doi/full/10.1080/10293523.2025.2553254
Key terms
- Portable Alpha
- An investment strategy that separates alpha (active return) from beta (market return), allowing investors to overlay active strategies on top of a passive market exposure using leverage or derivatives.
- Tail Risk Hedging
- A risk management strategy designed to protect a portfolio against extreme, rare market moves (tail events), typically using options or volatility derivatives.
- Skewness
- A statistical measure of the asymmetry of return distribution. Equities typically have negative skew (frequent small gains, occasional large losses). Reducing negative skew means reducing the frequency or severity of large crashes.
- Sharpe Ratio
- A measure of risk-adjusted return, calculated as (Portfolio Return - Risk-Free Rate) / Portfolio Volatility. A higher number indicates better compensation for each unit of risk taken.
- CAGR
- Compound Annual Growth Rate. The mean annual growth rate of an investment over a specified period of time longer than one year.
Frequently asked questions
What is Portable Alpha?
Portable Alpha is a strategy where an investor separates market exposure (beta) from active management (alpha). Typically, the beta is obtained efficiently using futures or swaps, leaving the remaining cash free to invest in uncorrelated active strategies (alpha) to generate excess returns. The returns are stacked, not blended.
How did the strategy perform during market crashes?
The strategy cut the maximum drawdown nearly in half (-19.1% vs -34.3%) compared to the global equity index. The combination of trend-following and tail risk hedging provided protection during both slow bear markets and sudden shocks.
What is the difference between trend following and tail risk hedging?
Trend following profits from sustained price moves over weeks or months (up or down). Tail risk hedging is designed to profit from extreme, sudden volatility events (crashes). Trend following is better for slow declines; tail hedging is better for rapid shocks.
Does this strategy reduce equity exposure?
No. A key feature of the Portable Alpha framework used in the paper is that it maintains 100% exposure to global equities at all times. The risk reduction comes from the gains in the hedging overlays offsetting losses in the equity portion, not from selling stocks.
What are the risks of this approach?
The main risks are leverage management and hedge cost. Because the alpha strategies are overlaid, the portfolio is effectively leveraged. Additionally, hedging strategies can act as a drag on performance during strong bull markets if the 'alpha' generated is negative (i.e., the cost of insurance).
How significant was the improvement in Sharpe ratio?
The Sharpe ratio increased from 0.37 to 0.66. This indicates that for every unit of risk taken, the Portable Alpha portfolio generated nearly twice as much excess return as the passive index.
What data did the study use?
The study used the MSCI ACWI (All Country World Index) as the proxy for global equities and tested the strategy using data that covered multiple market cycles, published in 2025.