There’s Only One Rule for Prediction Markets — Ignore It and You’re the Sucker

Picture a poker table. You’re playing your hand straight. But the guy across from you can see your cards — not because he’s clever, but because somebody’s holding a mirror behind you.

That’s a prediction market.

If you haven’t run into these yet, you will. They’re websites where you bet real money on what’s going to happen: elections, wars, what a CEO says on an earnings call, whether it rains Tuesday. Trading surged more than 400% last year to nearly $64 billion.

They’re being pitched to young people as a side hustle, a way to get ahead when rent and student loans have you pinned.

I’ve been writing about money since before most of these bettors were born. So let me be blunt. For the average person, this isn’t a side hustle. It’s a slow leak in your wallet.

Here’s why — and the one rule that keeps you out of the worst of it.

1. Most people who bet on these sites lose

The data is out there because some of these platforms run on public blockchains. Anyone can check the receipts.

A Wall Street Journal analysis found more than 70% of users on Polymarket, one of the biggest platforms, are losing money. Another academic study analyzed more than 70 million trades and found about 71% of users lose money.

On Kalshi, another major platform, losing users outnumber winners by almost 3 to 1.

Read that again. For every person bragging about a win, two or three others lost.

2. The few who win take almost everything

It gets worse. The winnings don’t get spread around. They pool at the very top.

That same Journal analysis found 1% of traders captured more than 76% of all profits. The top 0.1% — fewer than 2,000 accounts — grabbed 67% of everything, while the bottom 10% of users lost an average of $4,000 each.

Bloomberg looked at it another way. Over 100,000 accounts lost at least $1,000 in a single year — nearly double the number that won that much.

This isn’t a market. It’s a funnel, and you’re standing at the wide end.

3. The winners aren’t smarter — they’re faster

Here’s the part that should make you angry.

When researchers dug into who those big winners actually are, they didn’t find brilliant forecasters. They found automated bots that got into markets earlier and at better prices.

Get this. The regular retail traders actually picked the right outcome more often, but they still lost much more money because they traded late at bad prices.

So you can be right and still get cleaned out. Now hold that thought, because it’s about to get darker.

4. Some ‘bettors’ already know the answer

This is the one that truly gets me.

In January, U.S. forces captured Venezuelan leader Nicolás Maduro. A Green Beret named Master Sgt. Gannon Ken Van Dyke — a soldier who helped plan and execute the mission — allegedly made more than $400,000 betting on its timing. He placed 13 bets totaling roughly $33,000 in the days before the operation.

The Justice Department arrested him. He’s been charged with unlawful use of confidential government information, theft of non-public government information, and fraud.

Think about whoever sat on the other side of those bets. They were “predicting.” He was remembering.

Quick gut-check — if your money advice is coming from random online influencers, you’re playing a dangerous game. I’ve been a CPA since 1980 and writing about money since before the internet existed. Sign up for the free Money Talks Newsletter and get expert advice that’s been tested by time.

5. It’s not a one-off — it’s a pattern

Maybe you’re thinking that soldier was a single bad apple. He wasn’t.

Around the U.S. and Israeli military strikes on Iran, a single trader reportedly made nearly $1 million with a 93% success rate, placing bets hours before strikes the public knew nothing about. A separate group of 38 accounts netted more than $2 million on one round of strikes, after being funded the prior week.

And it isn’t just war. In one Kalshi enforcement action, a political candidate traded contracts on his own candidacy. In another, an employee tied to a YouTube channel traded contracts on the channel’s own videos.

Soldiers, politicians, insiders. Anywhere there’s a secret, somebody could be trying to use it to cheat.

6. Even Washington is backing away from these things

When the people who write the laws won’t touch something, pay attention.

The Senate unanimously passed a resolution barring its members from trading on prediction markets, and the White House warned staff against using nonpublic information to trade.

The director of enforcement of the Commodity Futures Trading Commission (CFTC) named insider trading in prediction markets a “top priority,” knocking down what he called a myth that insider trading doesn’t apply to these platforms.

Even President Donald Trump, asked about the betting frenzy, said the whole world “has become somewhat of a casino.”

When everyone in charge is heading for the exit, notice which way they’re walking.

7. The one rule that protects you

So here’s the rule. Burn it into your memory.

If it’s even theoretically possible for anyone — anyone — to have advance information about how a bet turns out, don’t make that bet.

Not “probably won’t happen to me.” Not “what are the odds.” If a soldier, a staffer, an executive, an editor, or some person three offices down from the decision could know the outcome before you do, then you’re the sucker at the table.

That rule wipes out most of what these sites offer. Wars. Politics. Corporate announcements. What somebody says on a broadcast. All of it fails the test.

And honestly? Even the bets that pass the test still leave you fighting bots for scraps with a 70% chance of losing. So the rule isn’t really “be careful.” It’s closer to “just don’t.”

Look, I won’t tell you that you can never have fun with your money. If you want to put $20 on a game the way you’d spend $20 on a movie — knowing it’s gone — that’s entertainment, and that’s your call.

But that’s not how prediction markets are being sold. They’re sold as smart. As an edge.

The truth is the opposite. The world is full of people who’ll do anything to make money, including cheat, and these platforms hand them a place to do it while you cover the bill.

Your financial freedom won’t come from guessing what happens next. It comes from spending less than you make and investing the difference patiently, the same habits that actually build wealth over time. That’s slow. It’s boring. It also works.

If you want a real side hustle, there are legitimate ones worth your time — a rigged casino isn’t one of them. And if betting has already crept past entertainment for you or someone you love, learn to recognize the warning signs of a gambling problem before it costs you more than money.

The flashy bet? Leave it on the table. Especially when you can’t see everyone else’s cards, but somebody can see yours.