Can you "insider trade" a prediction market? What the 2026 probes actually mean

In May 2026 the US House Oversight Committee opened an investigation into Polymarket and Kalshi, the two largest prediction-market platforms. The concern, as reported by CNBC and CoinDesk, is that some government employees may be trading on non-public information — placing bets on policy or national-security events they had a hand in shaping. It is a striking headline, and it raises a question worth answering carefully: can you even "insider trade" a prediction market, and if so, what does that mean for an ordinary trader?

What set off the investigation

Prediction markets have been in the political spotlight all year. Traders placed unusually well-timed positions ahead of US military actions abroad, and one Polymarket account reportedly earned around $400,000 in January by correctly calling a foreign leader's ouster before it was public. In letters to Polymarket's Shayne Coplan and Kalshi's Tarek Mansour, committee chairman James Comer asked how the platforms verify identities, enforce geographic restrictions, and flag anomalous trading. In other words: do they know who is trading, and can they spot someone who seems to know the future?

The platforms had already moved. In March 2026, both Kalshi and Polymarket announced measures aimed at curbing insider trading and aligning with guidance from the Commodity Futures Trading Commission (CFTC). If you want the wider regulatory picture, we covered it in what the CFTC's new prediction-market rules mean and in why European regulators are warning about prediction markets.

Why this is trickier than it sounds

Here is the twist. On a stock exchange, insider trading is clearly illegal: trading a company's shares on material non-public information is fraud against other shareholders. Prediction markets are different by design. As we explain in what is a prediction market, a market's job is to gather scattered information and squeeze it into a single price. When someone who knows something trades, the price moves toward the truth. That is the whole point.

Robin Hanson, the economist who helped build the theory behind these markets, has made exactly this argument: informed trading is not a bug, it is the mechanism that makes prediction markets accurate. If you ban everyone with useful private knowledge, you are left with a market that only reflects public guesses.

So the debate is not really "should informed people trade" — it is "which information is fair game." A weather forecaster trading a rain market is using expertise. A defence official trading a market on a military strike they helped plan is using secret, position-derived information, and may be breaking laws that have nothing to do with the market itself. The line is about the source of the edge, not the act of being well-informed.

Where the line sits

A few distinctions help clarify what regulators are actually worried about:

Public analysis is fine. Reading news faster, building better models, or spotting a pattern others missed is the ordinary work of a sharp trader — and it is what makes prices trustworthy. See are prediction markets accurate for why that matters.

Confidential, duty-bound information is the problem. If your edge comes from a government secret, a signed-but-unannounced deal, or privileged access you had a legal duty to protect, trading on it can be illegal regardless of the venue.

Manipulation is a separate issue. Deliberately moving a thinly traded market to trigger a payout, or coordinating trades to create a false signal, is a distinct concern from trading on private knowledge.

What it means for you

For an everyday trader in Europe or anywhere else, none of this describes your situation. You are not sitting on state secrets; you are weighing public information and forming a view. The investigation is aimed at a narrow group with privileged access, and the platforms are responding with better identity checks and trade monitoring — which, if anything, makes markets fairer for regular participants.

The useful takeaway is a mental model: a prediction-market price is a running tally of what informed people believe. When it moves sharply for no visible reason, someone may know something you do not — and that is a signal to slow down, not to chase. Reading those moves well is a skill, and it is one you can practise without risking a cent. On Outcomer you can trade real markets with virtual money, watch how prices absorb new information, and build intuition before anything is on the line. That is a better use of the news than worrying about a probe that was never about you.