Why Long-Term Strategy Matters More Than Seasonal Patterns

Each year, September carries a reputation for being one of the more challenging months for the markets. Historically, from 1950 to 2024, the S&P 500 has averaged a return of –0.68% in September, compared to an average +0.65% gain across other months.

This recurring pattern, often called the “September Effect,” is supported by decades of data. But here’s the important truth: while trends can offer context, they aren’t reliable predictors of what will happen next. In fact, nearly half of all Septembers have delivered positive returns—and in standout years like 2010, the market rallied almost 9% during the month.

The takeaway? Historical averages provide perspective, not certainty. Basing your investment decisions solely on seasonal patterns can lead to missed opportunities or poorly timed moves.

Why Seasonal Trends Are Limited

While it’s natural to look for patterns, there are three key reasons why calendar-based trends like the September Effect can only tell part of the story:

• Markets are dynamic: Economic policy, corporate earnings, and global events shift year to year. No calendar effect can fully account for these ever-changing factors.

• Volatility works both ways: While some Septembers have been negative, others have delivered strong gains. Timing the market based on averages can backfire.

• Short-term headlines add noise: Focusing too narrowly on a single month can lead to emotional reactions and poor decision-making.

Where to Focus Instead

Rather than attempting to anticipate short-term market moves, it’s far more effective to build and stick to a strong, personalized long-term strategy:

• Review your portfolio regularly to ensure it aligns with your goals and comfort level with risk.

• Stay the course when temporary volatility strikes—emotional reactions to headlines often do more harm than good.

• Work with a fiduciary advisor who can provide guidance rooted in sound planning, not market timing.

The Bottom Line

Seasonal market patterns like the September Effect can provide interesting historical context—but they shouldn’t dictate your financial decisions.

A successful investment strategy is built on discipline, diversification, and alignment with your personal goals and risk tolerance, not seasonal noise. Stay focused on what you can control, and let the short-term fluctuations take care of themselves.

At Whitener Capital Management, we take a comprehensive approach to financial planning. As fiduciaries, we are legally bound to put our clients’ interests first—helping you navigate market changes with a plan designed specifically for your needs and long-term goals.

If you’re unsure whether your current portfolio truly reflects your objectives, reach out to us today to schedule a conversation. A strong plan, backed by fiduciary guidance, can make all the difference in reaching financial independence.

Get in touch: whitenercapital.com/contact