Crypto contracts on Kalshi and Polymarket combined for a record $2.7 billion of notional volume in a single week, driven mostly by short-term bets on where bitcoin goes next, according to a WuBlockchain figure reported by Bitcoin.com News on October 24. The engine is the 15-minute market. On Kalshi, crypto volume reached about $8.17 billion between September 1 and 28, and roughly $7 billion of that, 86%, came from 15-minute contracts, lifting crypto from about 2.6% of the platform's total volume before the format launched to 14.5% in September. Polymarket's US platform did $91.76 million in its 15-minute bitcoin markets in their first full week, September 23 to 29, with daily volume rising from $2.40 million to $27.71 million and transactions from 63,650 to 739,034 over those days. Crypto now ranks second only to sports on both platforms. A 15-minute contract on bitcoin's direction works much like a very short-dated binary option, and the growth comes as Missouri has served Kalshi and Polymarket with cease-and-desist orders, as Bitcoin.com News reported last week. The figures on each platform come from secondary sources the article links to without fully attributing, so treat the breakdown as approximate.