Seasoned Wall Street investors have long cherished their traditional market adages, many of which have proven surprisingly effective over time. For instance, the post-Christmas 'Santa Claus rally' frequently boosts stock prices into the new year, while the 'halloween indicator' highlights how equities often perform better during the colder months. Perhaps the most famous of these sayings is 'sell in May and go away', which suggests that stocks typically stagnate over the summer, making it wise to liquidate positions and wait on the sidelines.
Historical Evidence and Modern Challenges
Historical data largely supports this seasonal pattern. Since 1990, the S&P 500 index has averaged a modest 3 percent gain from May to October, compared to a much stronger 6.3 percent average increase from November to April. However, for the summer of 2026, financial experts are cautioning that blindly following this old maxim could be a costly error. A growing chorus of analysts is now advising investors to adopt a more nuanced approach: remain invested in the market, but strategically reallocate assets.
The Case for Defensive Stock Rotation
Financial analyst Mark Hulbert argues that instead of exiting stocks entirely, investors should rotate into so-called 'defensive stocks' for the summer season. These are shares in companies that provide stable returns regardless of economic fluctuations, often referred to as 'safe-haven assets' or 'non-cyclical stocks'. They typically belong to sectors like healthcare and consumer staples, which sell essential goods and services that people continue to purchase even during downturns.
Hulbert's strategy is endorsed by Sam Stovall, chief investment strategist at CFRA Research. Stovall has validated the historical accuracy of the 'sell in May' wisdom, demonstrating that markets indeed experience higher returns and lower volatility from November through April compared to the May-October period. Building on this insight, he has developed a specialised seasonal index that alternates between high-growth and defensive sectors based on the time of year. Stovall advocates for 'rotating in May' rather than selling outright.
Practical Implementation Through ETFs
Rather than converting holdings to cash in May, Hulbert recommends investing in two exchange-traded funds (ETFs) that track Stovall's index: the Consumer Staples Select Sector SPDR Fund (XLP) and the Health Care Select Sector SPDR Fund (XLV). These ETFs encompass hundreds of companies in essential sectors and charge minimal annual fees of just 0.08 percent, offering a cost-effective way to gain exposure to defensive stocks. This approach aims to provide portfolio stability and peace of mind during the summer months, potentially benefiting retirement accounts like 401(k)s.
Potential Disruptors to Seasonal Patterns
Nevertheless, the stock market is often subject to unpredictable events—such as viral pandemics or global financial crises—that can disrupt the seasonal trends implied by phrases like 'sell in May and go away'. Charlie McElligott, a managing director at Nomura, warns that two significant factors could undermine Hulbert's rotation strategy for 2026.
First, a resurgence of the energy crisis stemming from Middle East conflicts could lead to continued market volatility due to oil supply shortages and price spikes. Sustained high energy prices might exacerbate inflation, prompting central banks to aggressively raise interest rates. This ties into McElligott's second concern: a potential bond market selloff. He cautions that energy shortages combined with central bank tightening could stifle economic growth in the US and globally, potentially triggering a recession.
In such a scenario, many investors might view cash as the safest haven during an economic downturn, challenging the efficacy of even defensive stock strategies. Thus, while seasonal wisdom offers valuable insights, it must be balanced against broader economic risks and unforeseen developments.
