The stock market

The market's long-run returns are anchored in the fact that publicly-traded companies in aggregate produce profits that grow over time. The growth comes from several sources. Economic growth more people, more productivity, more demand produces more revenue. Technological innovation raises profit margins. Market concentration lets winners capture scale economies. Together these forces have produced aggregate corporate profits that have grown, with interruptions, for over a century.

The investor's share of these profits comes through ownership. When you hold a broad-market index fund, you own a small piece of every major publicly-traded company. As aggregate profits grow, your share grows proportionally. The compounding of these growing profits over decades is what produces the substantial real returns stocks have delivered. The specific return any individual realizes depends on when they bought, when they sold, and how long they held. But the long-run average for someone who held broadly and consistently has been remarkably durable across economic conditions.

The seven-percent average conceals risks that matter for individual investors. First, sequence-of-returns risk. A large loss early in an investor's career can leave insufficient capital to benefit from the subsequent recovery. Someone who retired in 2000 and drew income through the 2000-2002 crash faced a much harder retirement than someone who retired in 2010. The same long-run average produces different outcomes depending on when the major drawdowns occur. Planning around this is substantially what retirement planning and mid-career asset allocation are about.

Second, specific-company risk. An investor putting everything into one company can lose it all if the company goes bankrupt. The list of major firms that went from apparent permanence to zero is long Enron, Lehman, various dot-coms whose names are no longer recognizable. Aggregate market returns assume diversification; investors who concentrate bear risks the averages do not capture. Index funds substantially eliminate this. Individual stock picking exposes investors to it constantly.

The stock market is a genuinely good vehicle for long-run wealth for people who can sustain the discipline it requires — regular contributions, diversification, holding through downturns, avoiding behavioral pitfalls. The discipline is harder than it sounds. Most people underperform the simple strategy they started with picking stocks badly, timing wrong, pulling out during drawdowns and missing the recovery. The gap between the strategy that would work and the one most people actually execute is substantial.

The market also has distributional implications the return number does not capture. Benefits flow disproportionately to those who already have capital, because compounding works on whatever is actually invested. The bottom half of American households own roughly one percent of all stocks. The top ten percent own roughly eighty. The seven-percent return is a compound rate on starting capital, and starting capital is itself a function of wealth already accumulated. The stock market is a wealth multiplier for those who can participate, and participation is uneven in ways that mirror broader wealth inequality.

The stock market matters as a subject because it is the primary mechanism through which the ordinary people who do save get to participate in the growth of the productive economy. The alternative holding cash or low-yield bonds, staying out of ownership of any productive assets has historically produced substantially worse long-run outcomes for people trying to build wealth. Understanding how the stock market actually works, including its specific risks and limits, is a prerequisite to making good financial decisions over a lifetime. The absence of this understanding, which is distressingly common in the general population, produces predictable errors that compound into meaningfully worse financial outcomes than reasonable participation would produce.