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- Three major prediction market platforms recently generated over nineteen billion dollars in combined weekly trading volume late last month.
- Industry leader Kalshi maintained massive market dominance, while an emerging competitor experienced significant growth utilizing popular football combination contracts.
Kalshi, Polymarket US, and Polymarket International combined for about $19.46 billion in trading volume from Sept. 21-27, up 3.9% from the prior week, according to DeFi Rate data cited by ReadWrite.
The new total, up from $18.72 billion the week before, points to continued growth in the U.S.-focused prediction market segment. The gain was driven mainly by Kalshi, which remained the clear market leader, and Polymarket US, which posted the largest weekly percentage increase.
Kalshi sets another record and keeps dominant share
Kalshi’s weekly volume rose 2.6% to a record $15.66 billion, giving it 80.5% of the combined total across the three platforms tracked. It also set a fresh daily high of $3.24 billion on Sunday.
That leaves the market heavily concentrated. Kalshi and Polymarket US together accounted for just over 95% of all volume across the three venues in DeFi Rate’s tracking.
Polymarket US handled $2.83 billion for the week, up 21% from the previous period. Its week-over-week gain of $491.6 million exceeded Kalshi’s increase of $395.4 million, even though Kalshi remained much larger overall.
Combination contracts drive most of Polymarket US growth
A large share of Polymarket US’s jump came from combination contracts. Volume in that segment climbed 44.4%, from $1.06 billion to $1.53 billion.
Combination contracts accounted for 95.9% of Polymarket US’s weekly increase. They also grew from 45.4% of the platform’s volume in the prior week to 54.1% in the latest one.
The platform’s largest individual markets were tied to football. The top market, Colts-Chiefs, generated $27.67 million in volume, followed by Giants-Rams at $23.23 million. All 10 of Polymarket US’s biggest individual markets were football-related, though those 10 markets represented only 4.4% of total platform volume.
Sports and bitcoin markets show where activity is landing
By category, NFL volume reached $267.0 million, while tennis drew $263.1 million, college football brought in $225.6 million, and MLB generated $201.8 million.
Bitcoin markets also surged, rising from roughly $453,000 in the prior week to $50.7 million, largely through 15-minute and hourly contracts.
Not every platform gained. Polymarket International fell 13.5% week over week, declining from about $1.11 billion to $964.1 million.
The latest figures show a prediction market landscape still led by Kalshi, with Polymarket US gaining momentum through combination products and sports-linked contracts that continue to draw engagement from across the sports betting and online casino space.
Source: As reported by news.google.com.
