Political positions loom larger than trading share across Kalshi and Polymarket
The October report, using Artemis data across 11 platforms, puts total October volume at a record 121.28 billion dollars with open interest at 3.13 billion dollars. Political open interest rose 52 percent in October to 1.01 billion dollars in the month before the midterms.
Trading share and outstanding positions diverge
Politics and elections accounted for 4.5 percent of volume on Kalshi and Polymarket over the past twelve months, but 41.2 percent of open interest, according to VIP-Grinders. The figures show a substantial gap between the category’s share of trading activity and its share of outstanding positions.
Those measures describe different aspects of market participation. The relatively small volume share does not translate into a similarly small presence in open interest.
October reaches a volume record
VIP-Grinders’ October report, drawing on Artemis data across 11 platforms, put total October volume at a record 121.28 billion dollars. Open interest stood at 3.13 billion dollars.
Political open interest increased 52 percent in October to 1.01 billion dollars, according to VIP-Grinders. That growth came in the month before the midterms.
The report therefore presents two distinct comparisons: a twelve-month breakdown for Kalshi and Polymarket, and an October snapshot spanning 11 platforms. Keeping those scopes separate is important when assessing political markets’ weight.
What it means for prediction markets
- Volume alone gives an incomplete picture: Politics and elections represented 4.5 percent of Kalshi and Polymarket volume, yet 41.2 percent of their open interest over the past twelve months.
- Political exposure expanded before the midterms: The 52 percent October increase brought political open interest to 1.01 billion dollars.
- These figures are not election forecasts: They describe activity and outstanding positions, rather than probabilities for particular outcomes.
Sources & attribution
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Full attribution under the Digital Millennium Copyright Act (DMCA), 17 U.S.C. § 512: this article is an original report by Infiniti Intelligence that summarizes the reporting of the publishers named above, links to their original work, and reproduces no protected expression beyond brief factual reference and in-line attribution (“according to VIP-Grinders”). All rights in the underlying reporting remain with the publishers listed; nothing here implies endorsement by or affiliation with them. Rights holders may request correction, update or removal through the contact address published at infiniti.w3ai.io.
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