Bitcoin Bettors Push Kalshi and Polymarket to a Record $2.7B Week

What Set the Record Exactly?

Weekly notional volume in crypto-related contracts on Kalshi and Polymarket reached a record $2.7 billion, with most of that money going into short-term bets on bitcoin and other crypto price moves. Consequently, crypto now ranks second only to sports on both platforms.

Bitcoin spent the past week chopping between roughly $80,000 and $84,000, a small range that can reward quick in-and-out trades.

15-Minute Markets Are Eating Everything

On Kalshi, crypto volume reached about $8.17 billion between Sept. 1 and 28, with roughly $7 billion, or 86%, coming from 15-minute markets. Crypto’s share of Kalshi’s total volume jumped from about 2.6% before the format launched to 14.5% in September.

Polymarket’s U.S. platform moved even faster and its 15-minute bitcoin markets did $91.76 million in their first full week, from Sept. 23 to 29. Daily volume climbed from $2.40 million to $27.71 million, and reported transactions grew from 63,650 to 739,034 over the same stretch.

For many users, these contracts work like a simpler, capped-risk version of leveraged trading where one can be wrong, but can’t get liquidated.

Who Is Opening The US Doors?

Coinbase’s prediction market offering is powered by Kalshi, and wallet maker Phantom has started a staged U.S. rollout of in-wallet markets. Phantom’s U.S. contracts cost $0.02 per contract, split between Phantom and Kalshi, plus a small network fee. Trades are funded at Kalshi, and the Kalshi balance does not show up in the wallet itself.

A Bloomberg analysis published recently posited the push as a response to declining spot trading volumes, with exchanges looking for a new product that keeps retail users engaged.

Are Traders Betting Big on Upside?

The simple answer is not exactly, as short-dated contracts are mostly about direction, not conviction. Longer-dated markets tell a cautionary tale because on options platform Derive, the implied odds of bitcoin reaching $100,000 by Christmas rose from 9.7% to 12% this week, even as spot bitcoin ETFs lost $635.6 million on Thursday.

That growing parity between fast bets and slow money seems to be indicative of a broader view on the desk, with several analysts telling Bitcoin.com News that bitcoin’s price won’t break $100K by the end of 2026.

What Could Slow the Boom?

Bloomberg pointed to legal challenges against sports contracts in several U.S. states, adding that their confluence could make crypto exchanges more cautious about expanding into prediction markets. Scrutiny is rising elsewhere, too, since the Pentagon just banned military insider trading on Polymarket and Kalshi after a $400,000 betting scandal shook the market.

Political support has not disappeared either, with Florida gubernatorial candidate Byron Donalds recently talking about prediction markets with Bitcoin.com News with a sense of optimism and caution. That said, the numbers say demand is still running ahead of the rulebook, one 15-minute bet at a time.

Defense Secretary Pete Hegseth has prohibited U.S. military personnel and Pentagon employees from using nonpublic information to trade on prediction…