What is a Ponzi scheme? How the fraud works

A Ponzi scheme is an investment fraud in which the "returns" paid to earlier investors come from money put in by newer ones, not from any real profit. The organizer promises high, steady returns, pays them out of fresh deposits, and keeps the rest. Because the money owed grows faster than new money can arrive, every Ponzi scheme eventually collapses, usually leaving most investors with large losses.

In short

• A Ponzi scheme has no real business making the returns it reports; old investors are paid with new investors' money.
• It collapses when new money slows or too many people ask for their money back at once, as Charles Ponzi's did in 1920 and Bernard Madoff's did in 2008.
• The warning signs are well known: high returns with little or no risk, returns that never wobble, unregistered sellers and trouble taking money out.

How does a Ponzi scheme work?

The organizer tells investors their money will go into some clever strategy: currency trades, property, a secret trading method, crypto arbitrage. In fact, little or none of it is invested. The SEC defines a Ponzi scheme as "an investment fraud that involves the payment of purported returns to existing investors" from funds contributed by new investors. Investors receive statements showing their balances growing, and some take cash out. That cash is simply other people's deposits.

Early investors who are paid on time become the scheme's best salespeople. They tell friends, family and colleagues, often in the same church, community or club, which is why regulators call this "affinity fraud". Many investors never ask for their money back, because their statements show it growing, and that is what keeps the scheme going.

Why must a Ponzi scheme collapse? A worked example

Follow a small scheme that promises investors 20% a year and invests nothing. Each year, investors take their 20% out in cash. New investors bring in $10 million in each of the first three years, then recruiting dries up.

Year	New money in	Total investors think they have	Paid out this year (20%)	Cash actually held	Gap between promise and cash
1	$10m	$10m	$2m	$8m	$2m
2	$10m	$20m	$4m	$14m	$6m
3	$10m	$30m	$6m	$18m	$12m
4	$0	$30m	$6m	$12m	$18m

While new money keeps arriving, payouts grow every year, because they are owed on everything ever put in. The gap between what investors think they own and what is really there widens every year, even before the organizer takes a cent for himself. In year 4, with no new money, the cash pile shrinks for the first time. If investors then rush to withdraw their $30 million, only $12 million exists. A Ponzi scheme doesn't fail because something goes wrong; it is built to fail, and only new money delays the day. Real schemes collapse faster, because organizers spend investors' money on themselves.

Who was Charles Ponzi?

Charles Ponzi was an Italian immigrant in Boston. In 1920 he promised investors a 50% return in 45 days, according to History.com. His story was arbitrage in international reply coupons, slips sold in one country that could be swapped for postage stamps in another. Coupons bought cheaply in Europe could, in theory, be redeemed for more in the United States. The price gap was real, but the coupons were far too few, and too hard to redeem, to pay anyone such returns. Ponzi paid early investors with later investors' money. Newspapers began asking questions in the summer of 1920, investors rushed to withdraw, and the scheme collapsed that August, having taken in about $10 million. His name stuck to the fraud, though he was not the first to run one.

What was the Madoff scheme?

Bernard Madoff ran the largest Ponzi scheme on record. He was a respected Wall Street figure and a former chairman of the Nasdaq stock market, and for decades his investment business reported steady gains of around 10% to 12% a year, through good markets and bad. Its strategy was said to involve trading options and stocks; in fact, for years, it made no trades at all.

The 2008 financial crisis brought it down. Investors needed cash and asked for about $7 billion back; Madoff couldn't pay. He confessed to his sons, who reported him, and he was arrested on 11 December 2008. On 12 March 2009 he pleaded guilty to 11 felony counts, and on 29 June 2009 he was sentenced to 150 years in prison, according to the US Attorney's Office. Customer statements had shown about $65 billion, much of it gains that never existed. The court-appointed trustee recovering money for victims reports that, as of 23 October 2026, it had recovered $15.5 billion and paid $14.8 billion to customers, much of it clawed back from investors who had withdrawn more than they put in.

How is a Ponzi scheme different from a pyramid scheme?

They are cousins but not twins.

	Ponzi scheme	Pyramid scheme
What investors are told	Their money is invested by an expert	They can earn by recruiting others
Who recruits	Mainly the organizer, plus word of mouth	Every member, as the main way to earn
Where money goes	To one central organizer	Up the levels, from new recruits to those above them
What investors know	They think there is a real investment	They often know recruiting is the point
Why it collapses	New deposits can't cover payouts	The supply of recruits runs out

The arithmetic of a pyramid is brutal. If each member must recruit six others, the 13th level of recruits below the founder would need more than 13 billion people, more than the world's population. The FTC draws the line between legal multi-level marketing and pyramid schemes by where the income comes from: sales to real customers, or recruiting.

How can you spot a Ponzi scheme?

The SEC's investor alert on Ponzi schemes using virtual currencies lists red flags that apply to any version:

• High returns with little or no risk. Real investments that pay more carry more risk.
• Overly consistent returns. Real investments go up and down. Madoff's steady 1% a month was itself the clue some analysts spotted.
• Unregistered investments and unlicensed sellers. Most Ponzi schemes involve people or products not registered with regulators.
• Secretive or complex strategies. If nobody can explain how the money is made, nobody can check it.
• Trouble with paperwork or withdrawals. Excuses, delays, or offers of higher returns to "roll over" instead of cashing out.
• Trust from a shared group rather than from checkable facts.

Modern versions often wear new clothes: crypto "yield" programs, trading bots, or the long online cons known as pig butchering scams. Not every collapse is a Ponzi scheme: FTX, for instance, was a crypto exchange whose founder was convicted of fraud for misusing customer deposits, a different crime. A label of Ponzi scheme is a legal finding, made by courts and regulators. This note explains how such frauds work; it isn't legal or financial advice.

Check yourself

• Explain in two sentences why a Ponzi scheme must collapse even if nobody steals a cent.
• What did Ponzi and Madoff each claim to be doing with investors' money?
• What is the key difference between a Ponzi scheme and a pyramid scheme?

Sources

• Ponzi schemes — U.S. Securities and Exchange Commission
• Investor alert: Ponzi schemes using virtual currencies — U.S. Securities and Exchange Commission, 2013
• Bernard Madoff sentenced to 150 years in prison — U.S. Attorney's Office, Southern District of New York, 2009
• Bernard L. Madoff Investment Securities LLC liquidation proceeding — SIPA Trustee for Bernard L. Madoff Investment Securities
• How did the Ponzi scheme get its name? — History.com
• Multi-level marketing businesses and pyramid schemes — Federal Trade Commission