What you can trade on Kalshi in the US isn't the same set you can trade on Polymarket offshore, and neither of those matches what a UK or Asian venue will let you touch. Prediction markets are carved up by regulation, and every jurisdiction draws the line in a slightly different place. That's a headache if you just want to place a bet. It's also where the interesting pricing gaps hide.
How the US actually regulates this
Here the CFTC treats prediction markets as event contracts. Kalshi runs as a regulated Designated Contract Market, which buys it legal clarity but boxes in what it's allowed to list. The CFTC has been fairly relaxed about economic and environmental contracts and has fought some ugly battles over political ones.
Because the stance keeps evolving, the menu of US-regulated contracts is never fixed. New contract types get proposed, sometimes approved, sometimes rejected, sometimes dragged into court. If you follow that process closely you can usually guess which markets are about to open and be there to provide liquidity early, when spreads are widest.
State rules pile on another layer. A few states restrict participation in event contracts even where they're legal federally. Most of that compliance burden lands on the platform rather than on you, but it decides which platforms you can even reach from where you sit.
Offshore and decentralized alternatives
Venues like Polymarket sit outside US jurisdiction, so they can list a far wider range of contracts. Political markets, entertainment, crypto-specific events, culturally touchy topics that US regulators would block, all of it is fair game.
The cost is legal risk. A US resident trading on an offshore venue is technically crossing CFTC rules. Enforcement at the individual level has been close to nothing, but "close to nothing" isn't zero. Polymarket itself got hit with a $1.4 million CFTC fine in 2022 and had to restructure, so the agency clearly notices.
Fully decentralized markets, where no single company runs the thing, sit in an even murkier spot. When a platform lives entirely in smart contracts on Ethereum with no central operator, the frameworks built around identifiable entities don't really know what to grab onto.
Where the opportunities are
All this fragmentation leaks into prices. The same event can trade on both Kalshi and Polymarket with different participant pools, different fee structures, and sometimes different resolution language. Those differences open up discrepancies that stick around, because arbitraging them means holding funded accounts on both sides and moving capital across jurisdictions, which most people won't bother doing.
The subtler effect is information. If Kalshi can't list a particular political contract but Polymarket can, Polymarket's price won't carry the read that US institutional traders would add if they were allowed in. So that price is probably less efficient than it would be under one unified rulebook, and if you've got a view on where those traders would push it, that's your edge.
The international picture
The UK handles prediction markets a lot like spread betting, which is a more permissive setup. Australia allows them under gambling licenses. Some Asian jurisdictions run de facto prediction markets through regulated betting exchanges. Each of those environments shapes the contracts on offer, who shows up to trade them, and how tight the pricing ends up being.
As the space grows I'd expect the rules to converge, though I wouldn't bet the house on it. The drift is toward more permissive frameworks, partly because prediction markets have earned some credibility as forecasting tools. But regulatory change moves slowly and unevenly, so don't plan around it.
Practical stuff to keep in mind
If you're trading across jurisdictions, be honest with yourself about the risk you're carrying.
- Use regulated platforms when one exists for the contract type you want.
- On offshore venues, know the legal framework you're operating under and size your exposure with that in mind.
- Assume the map redraws itself. Platforms and contract types that are live today might be gone next year, and things that are blocked now might open up.
At Blockcircle we route prediction-market orders across venues, and the boring reality is that most of the work is tracking which contracts are actually available where on any given week. Keep a list, check it before you build a position, and you'll avoid most of the surprises.