Explorer

Markets and venue leaders

Four different questions, kept separate: which venues are largest now, what leads each venue, where a particular event or contract is listed, and how much of the very same fixture two venues each traded.

Venue leaderboard

Recent reported scale, not an all-time contest between differently aged datasets.

Top markets by venue

The five largest markets inside each venue's own published window and unit. These are separate lists by design; they are not a blended cross-venue ranking.

Market finder

Search names, clubs, players, categories, outcomes, or ticker fragments across every supported venue. The default order is most recently traded.

Current coverage gap: ProphetX and Novig publish per-market files but are not yet normalized into the shared finder. Their absence here is a finder limitation, not an absence of markets or trading.

The same game, on two venues

Every fixture both Kalshi and Polymarket US listed, one dot each. Kalshi trades more of the same game in all six sports, but the gap runs from about .

The dashed line is parity and the fainter ones mark 10×, 100× and 1000×, so a dot between two guides traded that many times more on Kalshi. Only of fixtures sit above parity, where Polymarket US traded the larger book. Median ratio by league: .

About this comparison — read before quoting any number

This is not a random sample of either book. Kalshi publishes no per-fixture file; the only per-market data it publishes is two all-time leaderboards capped at its top 1,000 and 2,000 markets. A fixture outside those caps cannot appear here at all, so the shown are weighted towards big games — and towards games Kalshi traded heavily, which is the very quantity being compared. Read the ratios as "on the fixtures both venues listed and Kalshi traded a lot of", not as a market-share estimate.

The join is constructed, and it is checked. Polymarket US publishes a third-party sportradar_game_id on 92.5% of its events; Kalshi publishes no fixture identifier of any kind, so that id can only ever name one side and cannot be the key. Fixtures are matched on league, date and the unordered team pair through a 159-row crosswalk, with a one-day tolerance for games that cross midnight in one venue's timezone and not the other. Where both venues have settled, the two agree on the winner on of fixtures; the producer refuses to publish if a single one disagrees, because a disagreement would mean the crosswalk had mapped two different teams onto each other.

The two venues disagree about team order, and only in one league. All 47 flipped fixtures are IPL, and every IPL fixture is flipped; no other league has one. That is a listing convention, not an error, and nothing here is aligned by position — but it is why a comparison built on "first team" rather than team identity would be silently wrong for an entire sport.

Soccer is absent by construction. Polymarket lists a soccer fixture as three separate binary markets (home, away, draw) where Kalshi lists one, so the two are not the same object and a join would compare a two-outcome market against one leg of a three-outcome one.

Contracts are each venue's own unit and are not adjusted. Polymarket US contract counts are fractional; Kalshi's are whole.