Long-term investors in broad-market index funds like the Vanguard S&P 500 ETF have historically weathered market downturns, but past performance varies widely and short-term losses can be severe, especially during major crises
For many U.S. investors, low-cost index funds such as the Vanguard S&P 500 ETF offer a straightforward way to participate in the stock market's long-term growth. Yet the path is rarely smooth. Market volatility, economic shocks, and unexpected events can drive sharp declines, sometimes lasting years. While no one can predict the timing or depth of the next downturn, history offers perspective on what investors might expect over time.
Market performance is shaped by cycles of expansion and contraction. The S&P 500, a benchmark for large-cap U.S. stocks, has experienced both extended rallies and painful drawdowns. Over the past century, the index has delivered an average annual return close to 10%, but that figure masks wide swings. For example, the best 10-year stretch ended in 1959 with annualized gains above 21%, while the worst-ending in 1939-saw annualized losses of nearly 5% per year. These extremes highlight the risk of relying on short-term results, especially during periods of economic upheaval or financial crisis.
Long-Term Patterns and Outliers
Despite periodic setbacks, the S&P 500 has historically recovered from even severe downturns. Most 10-year periods since 1926 have produced positive total returns, but there are notable exceptions. The 1930s and the decade following the dot-com bubble both saw negative returns over a full decade, underscoring that recovery can take longer than many expect. Outside of these rare episodes, investors who stayed invested through market turbulence generally saw their portfolios regain lost ground and eventually reach new highs.
For context, the S&P 500's performance during the 2000s was shaped by two major shocks: the collapse of technology stocks and the global financial crisis. Investors who bought at the peak in early 2000 waited more than a decade to break even on a total return basis. This pattern is not unique to the U.S.; global markets have also experienced extended periods of stagnation or decline. As recent analysis of market cycles and sector-driven rallies shows, even strong long-term trends can be interrupted by concentrated losses or shifting economic fundamentals.
Risks of Short-Term Market Moves
Short-term market swings can be dramatic and unpredictable. While broad-market index funds are designed to reduce company-specific risk, they remain exposed to systemic shocks-such as recessions, geopolitical events, or sudden changes in monetary policy. Investors who panic and sell during downturns risk locking in losses, while those who hold on may face years of underperformance before markets recover. The timing of contributions and withdrawals can have a significant impact on realized returns, especially for those nearing retirement or with shorter investment horizons.
According to data from S&P Dow Jones Indices, the S&P 500 experienced an average intra-year decline of about 14% between 1980 and 2023, even as most calendar years ended with positive returns. This volatility can test investor discipline, particularly during periods of heightened uncertainty. Diversification, regular rebalancing, and a clear understanding of risk tolerance are essential tools for managing the psychological and financial impact of market downturns.
What History Suggests for Investors
While the S&P 500's long-term trajectory has been upward, the journey is marked by setbacks that can last years. Investors who focus solely on average returns may underestimate the risk of prolonged drawdowns or the challenge of staying invested during market stress. For those with long time horizons, maintaining a disciplined approach-such as dollar-cost averaging and avoiding emotional reactions to volatility-can help capture the benefits of market recoveries. But there is no guarantee that future recoveries will mirror the past, and each investor's situation is shaped by their goals, time frame, and risk capacity.
Understanding the difference between nominal and inflation-adjusted returns is also critical. While nominal returns may look attractive, inflation can erode purchasing power over time. Investors should also consider the impact of fees, taxes, and required minimum distributions on their long-term outcomes. Ultimately, the decision to invest in broad-market index funds should be grounded in a realistic assessment of both the potential rewards and the risks of temporary or extended losses.
Index funds like the Vanguard S&P 500 ETF are structured to track the performance of the underlying index, offering broad diversification and low fees. Yet even these funds cannot eliminate market risk. The S&P 500 is weighted by market capitalization, meaning that the largest companies have the greatest influence on returns. This can lead to periods where a handful of stocks drive overall performance, increasing concentration risk. Investors should periodically review their asset allocation, consider their exposure to different sectors, and ensure that their investment strategy aligns with their financial objectives and risk tolerance.
