Kalshi Posts $98.15bn October Notional Volume, Sets Daily $5.3bn Record

Kalshi recorded $98.15bn in October notional trading volume, its busiest month on record, and posted its first single-day total above $5bn on Oct. 24 at $5.30bn. TickerTracker reports Kalshi’s October volume was up 61.3% from September, with seven-day and daily reported open interest records also logged during the month.

Exchange-wide totals and the competitive backdrop

The eight exchanges tracked in TickerTracker’s October report—Kalshi, Polymarket US, DraftKings’ DKeX exchange, Novig, Underdog, Rothera, ProphetX and Crypto.com Derivatives North America (CDNA)—generated a combined $126.64bn in notional trading volume for October, a 65.3% increase from September.

Polymarket US ranked second with $14.77bn in October volume; this figure excludes Polymarket’s international venue. CDNA recorded $2.39bn, up 43.0% month-on-month. The totals in TickerTracker’s dataset count contracts at their full payout value and include repeated turnover; they do not measure customer spend or exchange revenue.

Which venues grew fastest

DraftKings’ DKeX, Novig and Underdog each more than doubled their monthly totals in October. DKeX grew 148.6% from September, Novig rose 126.1%, and Underdog increased 174.7%. Together with Rothera and ProphetX, those five exchanges accounted for $11.32bn in October volume, more than double their combined September total of $5.37bn—a 110.7% increase.

Among that group DKeX contributed the largest dollar increase, adding $2.69bn in monthly volume. Novig added $1.82bn and Underdog $1.26bn. DKeX, Novig and Underdog supplied 97.1% of the five exchanges’ combined increase. Growth at Rothera and ProphetX was slower, with month-on-month rises of 9.5% and 27.3% respectively.

Kalshi’s intra-month cadence and records

Kalshi broke its daily volume record on six separate dates in October. The busiest seven consecutive reporting dates—Oct. 22–28—generated $25.84bn, more than a quarter of October’s total. Trading averaged $3.17bn a day across the month.

Daily reported open interest first exceeded $2bn on Oct. 23 and reached a record $2.17bn on Oct. 30. Kalshi’s October total was 22.3 times the $4.40bn recorded in October 2025.

Product mix: combos dominate Kalshi and DKeX; sports rise elsewhere

Combos (multi-leg parlays) supplied the majority of growth at Kalshi and DKeX. TickerTracker counts contracts at full payout, so a five-cent combo paying $1 contributes $1 to notional volume.

Combos represented 83.9% of Kalshi’s $37.30bn increase from September, supplying $31.30bn of that gain. Volume outside combos at Kalshi reached $31.37bn, up 23.6% from September. Combos, standalone sports and crypto together made up 97.7% of Kalshi’s trading.

DKeX’s growth was similarly combo-driven: combos generated $3.27bn, or 72.8% of its total, while standalone sports contributed $1.22bn. Combos supplied 82.0% of DKeX’s additional monthly volume, raising their share from 59.0% in September.

Underdog showed a different mix. Its $1.54bn in combos represented 77.9% of its October volume, with standalone sports at $438.1m. Underdog’s sports volume rose to nearly 3.9 times September’s level, which reduced the combos share from 84.3%.

Polymarket US recorded a broader product mix. Combos accounted for $8.60bn or 58.2% of October volume, while standalone sports generated $4.57bn (representing 31.0%) and crypto was third at $1.52bn. Non-combo trading totaled $6.17bn, or 41.8% of Polymarket US’s reported trading, with standalone sports supplying roughly three-quarters of that non-combo activity. Daily trading averaged $476.6m, up from $290.0m in September, and the exchange set a daily record of $830.9m on Oct. 25.

Polymarket US’s crypto volume jumped to 11.6 times its September level—rising from $130.7m to $1.52bn—after the platform introduced 15-minute crypto markets on Sept. 22. Crypto represented 10.3% of Polymarket US’s October volume, compared with 1.5% in September. Polymarket US’s standalone sports share of 31.0% was about 13 percentage points higher than Kalshi’s 18.0%.

(For a closer read on sports figures see the sports section of our site.)

Football and Bitcoin: concentration within Kalshi’s top series

Standalone sports totals at Kalshi exclude combos. Football generated $6.27bn, or 35.4% of Kalshi’s standalone sports volume; the category includes both professional and college football. Selected contract types show NFL game-winner contracts produced $1.71bn. Adding NFL spreads, totals and pro football touchdown markets brings those four market types to $2.64bn. College football game winners, spreads and totals produced $2.59bn across three series.

Basketball volume at Kalshi was nearly eight times its September level. Football and basketball together added $3.29bn from September, exceeding the $2.70bn net increase across standalone sports because declines in baseball and tennis offset part of that growth.

Within Kalshi’s top 20 market types—series that aggregate trading across multiple events—90.7% of the exchange’s volume was concentrated. Bitcoin’s 15-minute contracts generated 76.2% of Kalshi’s crypto volume, making them the largest standalone market type; gold’s 15-minute contracts produced 62.5% of commodities volume.

Election markets generated $460.5m in October, 3.4 times September’s $136.1m, ahead of the U.S. midterm elections on Tuesday. Election markets nonetheless represented under 0.5% of Kalshi’s overall volume while accounting for 15.8% of open interest during the month.

Notable busiest days and cross-exchange peaks

DKeX, Novig and Underdog each recorded their busiest October day on Sunday, Oct. 25, with exchange-wide totals of $397.3m, $208.7m and $144.6m respectively. Kalshi’s single-day record of $5.30bn on Oct. 24 was the largest daily dollar figure among the tracked exchanges.

For operators and product teams tracking market composition, TickerTracker’s counting method—using full payout notional—means combo-heavy platforms will report larger notional totals relative to the same customer activity measured as turnover or revenue. Our coverage links product mix to reported metrics across venues in the b2b section.