Combo betting doubles to $41.7bn as rivals eat Kalshi’s share

Kalshi’s own combo volume still more than doubled to $35bn.

The hit

Kalshi’s combo betting market share dropped from 93.5% to 83.9% in the last 30 days, according to Aldrin Research data. Rivals Polymarket US, DKeX & Novig all grew faster in sports & combo trading, eating into Kalshi’s dominant position.

Why it matters

Kalshi is still the biggest sports & combo exchange, but the numbers show challengers are no longer just surviving, they’re taking real share during the football surge. For bettors, more competing exchanges could mean better pricing & product choice, even if Kalshi’s raw volumes keep climbing.

The record

Kalshi combo volume	more than doubled to $35bn (Aldrin Research)
Kalshi combined sports & combo volume	$30.2bn to $50bn (Aldrin Research)
Polymarket US combined volume	up 127% to $8.3bn, share up from 9.2% to 12.2% (Aldrin Research)
DKeX combined market share	up from 0.2% to 2.7% (Aldrin Research)
Novig combined volume growth	up 136%, share up from 1.5% to 2% (Aldrin Research)
Market-wide combo volume	more than doubled from $18.3bn to $41.7bn (Aldrin Research)

What happens next

Watch whether Polymarket US, DKeX & Novig keep gaining share once football volume normalises, & whether Kalshi responds with new combo products.

Sources: Kalshi Volume Surges, But Rivals Chip Away At Its Market Share

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