Americans are not supposed to be on Polymarket, but they were its biggest national political crowd over the last year anyway.

Wallets tied to the U.S. traded $571 million in notional value across Polymarket's political markets in the trailing 12 months, more than any other country and ahead of Hong Kong's $422 million, a new report by onchain analysis firm Allium found.

Polymarket blocks U.S. users by IP address because it cannot legally serve them. The block does little, Allium argues, because the platform runs on crypto rails, a wallet and stablecoins with no bank or broker in between. There is no account for a regulator to deny, no identity check to clear and no payment for a bank to stop, so a VPN, software that masks a user's location, plus an existing crypto wallet is enough to get in.

Allium's country tags come from wallets' onchain behavior rather than IP addresses, which is why the VPN that fools Polymarket's block does not hide a U.S. wallet from the data.

As such, Allium can tie only about 6% of Polymarket's political-market wallets to a country - so the firm says the figures should be read as directional rather than exact.

Polymarket did not immediately respond to request for comments ahead of U.S. market hours.

Meanwhile, a further interesting bit is what Americans bet on. Geopolitics made up 46% of U.S. notional against 36% for the platform as a whole, while elections drew 16% from U.S. wallets against 32% platform-wide, meaning the American crowd trades foreign wars at nearly three times the rate it trades the elections everyone else favors.

Of U.S. cohort's twelve biggest markets, five were bets on the Iran war. Its single largest, at $20.8 million, was a novelty market on whether Ukrainian President Volodymyr Zelenskyy would wear a suit.

Those are largely the markets regulated U.S. venues do not carry. Kalshi and Polymarket's compliant U.S. arm stick mostly to economic data, rate decisions and elections, so the demand flows to the offshore version that lists regime change and ceasefires.

The pattern regulators might fear is the one the data does not show.

On markets that have resolved, U.S. wallets backed the winner 81.9% of the time against 80.3% for everyone else, effectively no edge, and returns if held were nearly identical.

Americans bet more boldly, at one point placing 53% of their volume on a U.S. invasion of Iran when the rest of the market sat at 26%, but they picked winners no better.

Overall the report suggests that blocking access did not end U.S. participation, but moved the largest single political market offshore - visible onchain but beyond U.S. oversight, and the demand tilts toward exactly the markets U.S. rules restrict.