Introduction: Why Trends Last Longer Than They Should

Imagine two investors:

• One holds through the Dot-com bubble, the 2008 Financial Crisis, and the COVID-19 crash without ever reducing exposure.
• The other systematically cuts exposure when the market breaks its long-term trend.

In the end, their total returns might not differ drastically, but their maximum drawdowns and stress levels are radically different. This is exactly what Trend Following seeks to capture: letting bull markets run while cutting losses during major crashes.

Trend Following is an investment tactic distinguished by its historical robustness and geographical universality. It does not seek to predict the future. Instead, it exploits the persistence of price movements driven by massive capital flows and human cognitive biases, such as FOMO (Fear Of Missing Out) and herd behavior.

This article demonstrates that the superiority of this approach lies not necessarily in maximizing absolute returns during bull markets, but in asymmetric risk management—protecting capital during downturns while capturing the majority of uptrends.

We'll explore in detail the mechanics of moving averages, the distinction between absolute and relative momentum, and the necessary adaptation of defensive assets in a changing interest rate environment. Particular attention will be paid to implementing these strategies for the American investor, integrating the specific tax advantages of retirement accounts and the nuances of ETF selection.

1. Theoretical Foundations and Empirical Evidence

1.1 The Persistence of the Trend Anomaly

Quantitative analyses covering long periods have shown that financial markets do not follow a perfectly random path. There is a persistent statistical bias known as the "trend anomaly," which gives a significant historical advantage to trend-following strategies.

This persistence is explained by human nature of market participants and institutional constraints:

• Under-reaction: Investors tend to react slowly to initial new information, creating a slow price drift toward a new equilibrium.
• Over-reaction: Once a trend is established, investors over-react, extending the movement beyond fundamentals.
• Institutional Flows: Large funds, constrained by asset allocation mandates, inject liquidity progressively rather than immediately, fueling the trend's persistence.

Result: trends often last longer than expected.

1.2 Asymmetry of Returns

While "Buy and Hold" exposes the investor to 100% of market volatility, trend following aims for a model of "small losses, big gains". The goal is not to be right more than 50% of the time. Profitability comes from asymmetry: losses are mechanically limited by exit rules, while gains are uncapped.

The Mathematics of Recovery: If you have $100,000 and lose 50% (typical of a major crash), you are left with $50,000. To get back to $100,000, you need a +100% gain. However, if a trend strategy limits the drawdown to 20%, you keep $80,000. You only need a +25% gain to recover.

Analysis of backtests on the S&P 500 and MSCI World demonstrates that the long-term outperformance of trend following comes almost exclusively from its ability to avoid major drawdowns, such as the dot-com bubble burst (2000-2002) or the global financial crisis (2008).

2. Critical Analysis of Signal Methodologies

The precise definition of buy and sell "signals" is the core reactor of any trend-following strategy. Financial literature abounds with technical indicators, but rigorous analysis allows us to isolate methodologies that have withstood the test of time and changing market regimes.

2.1 The Simple Moving Average (SMA) 200

The most documented and robust method is the long-term Simple Moving Average (SMA). The rule is binary:

• Price > SMA: Bullish trend (Long position).
• Price < SMA: Bearish trend (Move to Cash or defensive assets).

Legendary trader Paul Tudor Jones famously used the 200-day rule to escape the 1987 crash. However, checking this signal daily exposes the investor to "market noise" and "whipsaws" (false signals), which erode performance through transaction costs and tax drag.

The Solution: Check the signal monthly. Monthly verification acts as a filter, offering similar risk-adjusted returns with drastically fewer transactions.

Chart of the SPY SPDR S&P 500 ETF Trust and its 200-day SMA:

In green are the areas where the price of SPY is above its 200 SMA (upward trend) and in red are the areas where the price of SPY is below its 200 SMA (downward trend).

2.2 The Golden Cross (50/200 Crossover): A Lagging Indicator

A popular alternative strategy is the "Golden Cross," which occurs when the short moving average (50 days) crosses above the long moving average (200 days). The inverse is the "Death Cross."

Although widely publicized, this indicator suffers from a major structural flaw for the long-term investor: lag. Since both components are lagged averages, the buy signal often triggers well after the market bottom has been reached, and the sell signal well after the top.

On the S&P 500, a Golden Cross strategy often underperforms a simple Price vs. SMA strategy because it spends too much time out of the market during recoveries.

2.3 Dual Momentum (GEM)

Gary Antonacci formalized the "Global Equities Momentum" (GEM) approach, widely considered the optimal architecture for individual investors. It combines two forces:

1. Relative Momentum: It compares the performance of two risky assets (typically the S&P 500 and MSCI World ex-US, or an international index) over a given period (typically 12 months). It selects the best-performing asset. This allows adaptation to economic cycles where the US underperforms the rest of the world, and vice-versa.
2. Absolute Momentum: Once the winning asset is selected, the strategy verifies if its trend is positive (return above the risk-free rate or price above the moving average). If the trend is negative, the strategy switches to a defensive asset.

Backtest results on the GEM strategy are compelling. From 1974 to 2013, this approach generated an average annual return of 17.4% with lower volatility than the market, vastly outperforming simple momentum or diversified buy-and-hold strategies. The key to this outperformance lies in the dynamic ability to "change horses" mid-race (Relative Momentum) while maintaining the ability to "dismount" in case of danger (Absolute Momentum).

3. Managing the Defensive Asset: A New Paradigm

2022 marked a fundamental break in trend-following history. Previously, Long-Term Treasuries (like TLT) were the ultimate hedge due to their negative correlation with stocks.

3.1 The Failure of Bonds in 2022

In 2022, high inflation and aggressive Fed rate hikes caused stock-bond correlation to turn positive. Both crashed simultaneously. Strategies using aggregate bonds (AGG) or long-term treasuries as a "safe haven" suffered a double loss.

3.2 The Superiority of T-Bills (Cash)

Post-2022 analysis demonstrates the imperative need to reduce the "duration" of the defensive asset during periods of inflationary uncertainty. The "risk-free" asset must be truly free of interest rate risk.

• Short-term Treasury Bills (T-Bills) or money market funds become the defensive asset of choice. ETFs like SHV, BIL, or SGOV offer capital preservation and a yield that adjusts quickly to rising rates.
• Updated backtests show that replacing aggregate bonds with T-Bills in momentum strategies would have avoided significant losses in the "safe" portion of the portfolio in 2022, thus preserving the strategy's relative outperformance.

4. Practical Implementation for the US Investor

For an American investor, the choice of account type is crucial for tax efficiency. The tax advantages of retirement accounts like Traditional IRAs, Roth IRAs, and 401(k)s can dramatically impact long-term returns, especially for active strategies like trend following.

4.1 Tax Considerations: The IRA Advantage

Roth IRA: The Optimal Vehicle

The Roth IRA is arguably the best account for implementing a trend-following strategy:

• All gains, regardless of how many times you trade, grow completely tax-free
• No taxes on withdrawals in retirement (age 59½+)
• No required minimum distributions (RMDs)
• Perfect for active strategies that generate multiple buy/sell signals

Traditional IRA and 401(k): Strong Alternatives

These accounts offer:

• Tax-deferred growth (no taxes on trades within the account)
• Immediate tax deduction on contributions
• Ideal for investors in high tax brackets now who expect lower brackets in retirement
• Note: Subject to RMDs starting at age 73

Taxable Brokerage Account: Last Resort

If retirement accounts are maxed out.

4.2 Selecting the Best US ETFs

or a trend-following strategy, prioritize ETFs with high liquidity, low expense ratios, and tight bid-ask spreads.

For Broad US Market Exposure (S&P 500)

For Global Market Exposure (MSCI World / ACWI)

For Defensive Assets (Risk-Off)

*Yields as of late 2024, will vary with Fed policy

Recommended Implementation: For a single-asset trend following strategy, VOO (S&P 500) or VT (Total World) paired with SGOV (T-Bills) offers the optimal combination of low costs, high liquidity, and tax efficiency within retirement accounts.

4.3 The Decisive Tax Advantage

The impact of taxes on an active strategy like trend following is often underestimated. In a taxable brokerage account, each rotation (selling the equity ETF to go to cash) triggers taxation of capital gains. This tax friction acts as a powerful brake on compound interest.

Example: In a taxable account with 20% long-term capital gains tax:

1. You invest $100,000 and it grows to $150,000
2. You sell to move to defensive assets
3. You owe $10,000 in taxes (20% of $50,000 gain)
4. You only have $140,000 to reinvest when the trend turns positive

In a Roth IRA or Traditional IRA:

1. You invest $100,000 and it grows to $150,000
2. You sell and reinvest the full $150,000
3. Zero tax friction on the trade

Over a 20-30 year horizon, this advantage can represent a difference in final capital of 30-50% or more compared to a taxable account.

Contribution Limits (2024)

• Roth IRA / Traditional IRA: $7,000/year ($8,000 if age 50+)
• 401(k): $23,000/year ($30,500 if age 50+)

Consider maximizing these limits before implementing strategies in taxable accounts

5. Strategy Protocol and Execution Rules

Based on the analysis, here is the optimal Trend Following protocol for a US investor.

5.1 The Strategy Rules

1. Asset Allocation

• Risk-On Asset (Bull Market): 100% in S&P 500 ETF (Ticker: VOO or SPY) or Total World ETF (Ticker: VT)
• Risk-Off Asset (Bear Market): 100% in Short-Term Treasury ETF (Ticker: SGOV or BIL) or Money Market Fund

2. The Signal

• Frequency: Monthly
• Indicator: 200-day Simple Moving Average (SMA 200)
• Calculation: Compare the ETF's closing price to the average of the last 200 days' closing prices

3. Trading Rules

• Check: Every month, compare the closing price of the Risk-On Asset to its SMA 200.
• IF Price > SMA 200: The trend is UP. Buy or Hold the Risk-On Asset. Stay 100% invested.
• IF Price < SMA 200: The trend is DOWN. Sell the Risk-On Asset. Move 100% of capital to SGOV/Cash.

4. Execution

• Timing: It's recommended to place orders the day after analysis, at the open or during the trading session, based on the signal calculated at the previous day's close.
• Discipline: strictly verify only once a month. Daily checking increases behavioral error (fear, FOMO, false signals).

Conclusion

The "best" investment strategy is not the one promising the most extravagant returns, but the one offering the highest robustness against uncertain economic regimes.

The analysis conducted in this article identifies the Monthly Absolute Momentum strategy on the S&P 500 or MSCI World indices, executed via low-cost ETFs within a Roth IRA or Traditional IRA, as optimal for the American investor. This approach combines:

• The power of diversification (US or global)
• Mechanical protection against deep bear markets through the 200-day moving average
• The security of Treasury yields during crisis periods
• Maximum tax efficiency

By adopting this methodology, the investor transforms their portfolio into a convex structure: capable of capturing wealth creation while possessing an automatic "circuit breaker" to preserve capital during financial storms. Success relies not on the model's complexity, but on the investor's psychological discipline to execute it, month after month, without deviation.

Disclaimer: This article is for educational purposes only and does not constitute financial advice. Past performance does not guarantee future results.

Updated on: 02/03/2026