Weekly non-sports prediction market volume across Kalshi and Polymarket climbed to a record $10 billion last week, according to Artemis data, extending a run of six consecutive weekly highs.

The figures show a sharp widening in market share between the two platforms. Kalshi accounted for $9.6 billion of the total, while Polymarket handled $344.2 million, leaving Kalshi with roughly 96% of the reported non-sports volume after the two were close to even only a few months earlier.

Kalshi widens the gap

The latest data points to a major change in the balance of activity between the two best-known prediction market venues outside sports. Artemis recorded Kalshi far ahead of Polymarket last week, continuing a trend that has accelerated since early summer.

The shift is notable because the market was near parity in early June. Since then, Kalshi has pulled away as trading activity increasingly concentrates on its contracts, particularly in categories grouped as non-sports markets.

Retail distribution appears to be the main driver

A key factor behind Kalshi’s expansion is where its contracts are being distributed. Robinhood, Coinbase, Webull and Moomoo all offer access to Kalshi markets, putting those contracts in front of large retail audiences that may not have been looking for prediction markets directly.

Polymarket does not have the same mainstream distribution channels cited in the report. That difference in visibility and accessibility appears to be helping Kalshi convert more general brokerage and app users into event-contract traders.

Why the headline volume can grow quickly

The structure of some contracts also matters when interpreting the reported totals. Short-duration products, such as hourly contracts on assets like Bitcoin, can open and settle within an hour, allowing the same deposited notional amount to be reused repeatedly through the day.

By contrast, longer-dated contracts can tie up capital for weeks, yet both short- and long-term markets feed into the same headline volume figures. The source article also notes that multi-leg combinations are counted according to the classification of the underlying contract, which can push more activity into the non-sports category.

Data sources do not match perfectly

The exact split between Kalshi and Polymarket depends in part on how data providers classify and count trades. Different trackers may assign activity differently based on factors such as on-chain flows or settlement methods.

Even with those differences, the broader pattern appears consistent across sources: Kalshi’s lead in non-sports prediction trading is increasing. The disagreement is over precise measurement rather than the direction of the trend.

What comes next

The source article says Kalshi’s reliance on outside distribution is also shaping how the market may evolve from here. Robinhood is developing Rothera to list event contracts directly, a move that could strengthen the distribution model that has already helped Kalshi expand.

For now, the confirmed takeaway is that non-sports prediction trading has reached a new weekly high and that Kalshi is capturing the vast majority of that activity, at least under the Artemis methodology cited in the report.

Source: Cryptopolitan