Every year, the US government collects vast amounts of data on the net worth of families across the country. Number crunchers at the Federal Reserve, the nation’s central bank, analyze Americans’ net income, credit card debt, the value of homes and mortgages, bank balances, investment portfolios, and more.

These data are cleaned up, dissected, tabulated, and published every three years as The Federal Reserve Survey of Consumer Finances. Notwithstanding its dry name, the report provides a fascinating yet sobering portrait of the wealth distribution in what is arguably one of the wealthiest countries on the planet. As students of the hard and soft sciences well know, the typical spread of randomly distributed data often resembles a bell curve, whether it’s the variation in performance on a standardized test or the height or weight of children in a fourth-grade class. Most data points cluster toward the average, creating a pronounced hump in the center of the curve, with fewer data points extending symmetrically outward on both sides. This distribution is so common that statisticians refer to it as the “normal distribution.” The wealth distribution in America stands in sharp contrast.

When the household net worth of all US families is mapped onto a graph, the resulting picture reveals a very skewed distribution of wealth.

As “The Wealth Spectrum of America” demonstrates, wealth is neither uniformly nor normally distributed. Instead, there is a “long tail,” implying a concentration of wealth among a few. In fact, a third of the nation’s wealth is shared by the bottom 93 percent of all families—those with a net worth below $1.5 million. A second third is shared by the roughly 6 percent of Americans who possess between $1.5 million and $7 million in net worth. The final third is controlled by just 1 percent of the population with upwards of $7 million, a group that includes the members of the elite Forbes 400, the business magazine’s famous annual ranking of US billionaires. The long tail of wealth distribution by household is in fact nothing new: throughout the Middle Ages in Europe and Asia, the nobility and landowning families maintained a firm grip on resources in their nations and enjoyed a gilded life, even as most of the population toiled in poverty. The Industrial Revolution brought vast improvements in living standards as power from steam, coal, and oil supplemented human labor, and democracy and property rights took hold in Western societies, lifting millions of people into the middle classes.

The distribution of wealth, while markedly uneven in the United States, is even more skewed when analyzed on a global scale. For instance, according to a recent report that carefully sources the world’s roughly $241 trillion in total wealth, the richest 1 percent of adults control 46 percent of global assets and the richest 10 percent control 86 percent. The bottom 50 percent hold less than 1 percent of the wealth. Indeed, recent work by French economist Thomas Piketty and collaborators points to wealth inequality as an inevitable consequence of the capitalistic system. This has in turn led to a robust debate over capitalism’s unintended consequences, such as inequality of opportunity, and what society or governments should do to address this.

With roughly 20 percent of the world’s population living on less than a dollar a day, one takeaway from our snapshot of wealth distribution is that Americans are comparatively lucky. Yet the reality is that most Americans’ financial situation is quite precarious. The figure above shows the US wealth spectrum by percentiles, one out of ten US households is bankrupt, possessing a net worth that is negative. Another ten percent have a total net worth of less than $4,300. One-third of all American families are either already bankrupt or just one cataclysmic event away from complete financial ruin, whether it’s a job layoff, a major medical emergency, or a bad traffic accident.

Such statistics reinforce something that most people already know intuitively: that even in America, a country whose founding mythology promises a shot at success and fortune to anyone who works hard, there is still a deep asymmetry between the sweat that it takes to build wealth and the ease with which it can all be lost.

Even in one of the richest countries on earth—a country, not incidentally, with few social safety nets—money is hard to come by for most families, and even harder to hang on to. The central lessons are clear: whatever degree of wealth you possess, you need a strategy that enables you to preserve what you have, regardless of the performance of the economy or financial markets. You must also maintain your standing on the wealth spectrum, by keeping pace with inflation and earning a return on your financial assets that is at least equivalent to the broader market return. And finally, if your aspirations include moving up the wealth spectrum or creating a lasting impact, you should be able to pursue your dreams without jeopardizing your financial safety.