Why is the U.S. onion market the only agricultural commodity where futures trading is banned? This one-of-a-kind regulatory anomaly traces back to one of the most incredible market manipulations in American financial history.
Here’s the fascinating story behind that ban!
Back in 1955, a New York onion farmer made a fortune by cornering the entire U.S. onion market, triggering a major market scandal.
By the time he was done, onions were literally flowing through the streets of America.
Who’s ready to dig into this incredible tale of speculation and manipulation?
Vince Kosuga saw himself as far more than a simple onion farmer. He ran a 5,000-acre farm devoted to growing onions in Pine Island, New York. But it was his side business — trading on the futures markets — that would earn him a reputation as notorious as it was lasting.
Originally, futures markets gave farmers an effective way to hedge their risk. They could sign contracts to sell their harvest at a fixed price on a future date, wiping out the risk tied to price swings in agricultural markets.
But Vince was mainly interested in using futures for speculation. That approach, a far cry from traditional hedging, would change his life.
He wanted to get rich, not just hedge his risk!
After a few unsuccessful runs trading wheat futures, Vince Kosuga had a revelation (a seemingly obvious one).
He knew everything there was to know about onions, so he should trade onions! He was going to pull off the greatest onion trade of all time…
The idea was simple. He wanted to seize the entire American onion market. Pulling off the plan, however, wasn’t quite so simple.
To get there, he had to own the vast majority of every onion in the country — harvested or still in the ground.
Vince didn’t go it alone, either: he partnered with Sam Siegel, a seasoned trader who knew the inner workings of the futures markets inside out. Together, the two thought big and started buying onions — lots of onions…
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They built secret warehouses across the country, buying and storing millions of onions. But that only covered the onions already harvested, which made up just a fraction of the total market.
So they started buying up futures contracts en masse, becoming the owners of every future American onion crop. A textbook “corner” to control supply and set the price — the exact opposite of a market maker’s legitimate role.
By the fall of 1955, Kosuga and Siegel had a stranglehold on the entire U.S. onion market — nearly 98% of the onions available in Chicago are said to have fallen under their control.
What’s more, nobody was aware of the sheer scale of their operation!
With that kind of control, they could move the price of onions however they pleased. Now it was time to move on to the cash-in phase.
Vince Kosuga’s Machiavellian plan swings into action: manipulation and massive short selling
They called a meeting with the major players in the onion market to deliver a message of brutal simplicity: “You belong to me.”
They could send the market soaring or crashing on a whim, while the people across the table — farmers and distributors — had to fall in line without a word.
So they agreed to buy 9 million pounds of onions at a price that suited Vince.
But Vince had another trick up his sleeve to pull off a double play!
He began betting against the price of onions by short selling futures contracts. By the spring of 1956, he had built a massive short position against onion prices. The trap was set. To better understand this mechanism for speculating on the downside, check out our guide to futures contracts.
He then emptied the onion warehouses, loaded up the trucks, and flooded the entire market with onions within a few days.
As enormous shipments of onions hit the futures exchange all at once — the Chicago Mercantile Exchange (CME), where these futures were traded — the price of onions began to collapse hard. Nobody wanted to be stuck holding all that unsellable stock.
So some trucks simply dumped their loads in the streets. The streets were literally flooded with Vince Kosuga’s onions.
The price of onions collapsed, dropping to 10 cents for a 50-pound bag — cheaper than the empty bag they came in!
Vince Kosuga cleaned house and pocketed a fortune.
The aftermath: the 1958 Onion Futures Act and its legal legacy
His short on the onion market earned him $8.5 million at the time — which, adjusted for inflation, is the equivalent of several tens of millions of dollars today (somewhere in the region of $95 to $100 million in 2026). Not bad for an onion farmer…
The anger against Vince was massive, as you can imagine.
Plenty of people had been ruined by his market manipulation, yet he never admitted to doing anything illegal. And indeed, under Anglo-American law, when a practice isn’t explicitly banned, it remains perfectly legal!
His trading license was suspended for 10 months and he had to pay a relatively modest fine. Still, his legacy lives on to this day in American financial legislation…
In 1958, President Eisenhower signed the Onion Futures Act, the law on onion futures, which flat-out bans the trading of futures contracts on the onion market.
To this day, onions remain the only agricultural commodity hit by a ban of this kind in the United States. And that’s how the legend of Vince Kosuga’s onion power play still lives on in the financial history books!
2026 update: the law is still in force (and has even been expanded)
Seventy years later, the Onion Futures Act has never been repealed: in 2026, it is quite simply illegal to trade onion futures in the United States. A tasty detail for fans of market trivia: since 2010, the text has been amended to also ban futures on movie box-office receipts (after intense lobbying from the Hollywood studios). So onions are no longer literally the only banned product — but they remain the only agricultural commodity affected, which keeps this anomaly as unique as ever.
Lessons today’s traders can draw from this historic manipulation
The moral of the story is whichever one works for you…
Personally, I take away several key lessons from this juicy futures anecdote:
- Derivatives can be highly profitable if you know how to use them intelligently, provided you master risk management.
- Always watch out for market manipulation, a phenomenon that still exists today. Cornering the entire supply to trap the sellers is, in fact, just the flip side of a short squeeze: in both cases, it’s an extreme imbalance between supply and demand that sends prices exploding (or imploding).
- Knowing an industry inside out is essential to investing in it successfully.
