Congressional contracts reach $431 million as report flags price sensitivity

Trading volume tied to 2026 House and Senate races reached $431 million across Kalshi, Polymarket and Polymarket US, according to RG’s reporting on findings from the Anti-Corruption Data Collective.

The collective counted 28,845 markets linked to those congressional contests. Total betting volume was nearly triple the level recorded during the 2024 cycle.

Volume rises, but prices remain sensitive

Kalshi accounted for more than $286 million of the total, according to RG. That places the platform’s contribution above half of the combined volume across the three venues.

The report also found that 96 percent of live congressional markets could see their prices shifted by five cents with $3,500 or less. That finding concerns the cost of moving prices, rather than the aggregate amount traded.

For readers tracking election probabilities, the two measures provide different information: substantial overall activity does not necessarily mean individual contracts are resistant to price changes.

What it means for prediction markets

• Activity has expanded: Volume nearly tripled from the 2024 cycle, across 28,845 markets tied to 2026 House and Senate races.
• Kalshi accounts for most volume: More than $286 million of the $431 million total came from that platform.
• Price moves need context: The reported sensitivity of 96 percent of live congressional markets suggests that a five-cent move need not reflect a large commitment of capital.