Library/On-Demand Combinatorial Event Markets on Kalshi: Instantiation, Concentration, and Effective Market Breadth
MicrostructureResearch Paper

On-Demand Combinatorial Event Markets on Kalshi: Instantiation, Concentration, and Effective Market Breadth

Maksym Nechepurenko·September 14, 2026·Academic Paper
ticker count is not economic breadth — three collections carry 7.6 million kalshi objects

Why It's Worth Reading

Kalshi's multivariate-event interface doesn't ship a catalogue of parlays; it mints market objects on demand from whatever legs a request names. Over one registered seven-day window the author pulled 7,611,594 unique REST tickers, created at roughly 1.09 million per day with heavy hourly bursts. The hierarchy then compresses hard: 5.26 million distinct event keys sit under just three observed collection keys, one of which holds 94.82 percent of all objects, and 66 million leg occurrences reduce to 83,701 primitives with an effective count near 720. Only 35.38 percent of objects had any volume or open interest at retrieval, REST and WebSocket surfaces overlap on a mere 276,177 tickers, and every observed 24-hour volume reading was zero. On-demand instantiation is a market-architecture phenomenon, not a storage artifact — ticker count is not economic breadth.

Extensive technical background assumed

Concepts

Platforms mentioned: Kalshi

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