# What Is the 30-Year Average of the Stock Market?

Summary：Learn about the 30-year average of the stock market, how it's calculated, and its implications for investing strategy. Don't rely on it alone as a predictor of future returns.

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What Is the 30-Year Average of the Stock Market?

If you're an investor or follow financial news, you may have heard about the "average return of the stock market" over various time periods. For example, you might have seen headlines like "The S&P 500 Has Returned X% Annually Over the Past Y Years." While these figures can be informative, they can also be misleading if you don't understand what they represent and how they are calculated. In this article, we'll focus on one of the most commonly cited averages: the 30-year average of the stock market. We'll explain what it means, how it's computed, and what implications it may have for yourinvesting strategy.

What is the 30-year average of the stock market?

The 30-year average of the stock market is a measure of the average annualized return of a broad equity index, such as the S&P 500, over a rolling 30-year period. This means that for each day, month, or year in the past 30 years, you can calculate the return of the index for that period, and then take the average of all those returns. For example, if you start with January 1, 1980, and look at the 30-year period ending on December 31, 2009, you would have 252 different 30-year periods to analyze. Each period would have a different starting and ending date, but the same length of 30 years. You would compute the return of the S&P 500 for each of these periods, and then take the average of those returns, which would be the 30-year average.

How is the 30-year average of the stock market calculated?

The 30-year average of the stock market can be calculated using different methods, depending on the data and assumptions used. However, a common way to do it is to use monthly prices or returns of the index, adjust them for inflation, and compound them over 30 years. This means that you would assume that you invested at the beginning of the 30-year period and held the index until the end of the period, reinvesting all dividends and interest. You would also adjust the returns for inflation, which means that you would express them in constant dollars, taking into account the changes in the general price level over the period. Finally, you would compound the returns, which means that you would multiply them together, as if you were earning interest on interest. The resulting figure is the annualized return of the index over that 30-year period.

What is the 30-year average of the stock market telling us?

The 30-year average of the stock market is a useful metric for long-term investors who want to know what kind of returns they can expect from investing in stocks over several decades. It's also a way to compare the performance of different periods, as it smooths out short-term fluctuations and captures the overall trend of the market. However, it's important to remember that the 30-year average is not a guarantee of future performance, nor is it a fixed number that always applies. The actual returns of the stock market can vary widely from the 30-year average, both in terms of magnitude and direction. For example, the 30-year average of the S&P 500 from 1980 to 2009 was about 11.2% per year, but the actual returns in some years ranged from -37% to +38%. Moreover, the 30-year average can change over time, as new data replaces old data and different market conditions prevail. For instance, the 30-year average of the S&P 500 from 1950 to 1979 was about 7.9% per year, but the 30-year average from 1960 to 1989 was about 5.6% per year, due to the bear market of the 1970s.

How can you use the 30-year average of the stock market in your investing?

The 30-year average of the stock market can be a useful benchmark for your investing goals, but it shouldn't be the only factor you consider. You should also take into account yourrisk tolerance, your time horizon, your financial needs, and your personal preferences. For example, if you're a young investor with a long time horizon and a high risk tolerance, you might aim for a higher return than the 30-year average, by investing in more aggressive stocks or asset classes. On the other hand, if you're a retired investor with a short time horizon and a low risk tolerance, you might aim for a lower return than the 30-year average, by investing in more conservative bonds or cash equivalents. In any case, you should diversify your portfolio and avoid making drastic changes based on short-term market movements or emotions.

Conclusion

The 30-year average of the stock market is a useful metric for understanding the historical performance of equities over a long period of time, but it's not a crystal ball for predicting future returns. It's important to use it as part of a broader investing strategy that takes into account your individual circumstances and goals. By doing so, you can improve your chances of achieving your financial dreams and weathering the ups and downs of the market.