tensorust/prediction-market-liquidity-sample

Prediction Market Liquidity Panel: free sample (Tensorust LLC)

99,817 Kalshi and Polymarket markets with volume, open interest, bid, ask and spread, rolled up by category: where prediction-market liquidity actually sits.

Headline: Prediction market volume is concentrated in a handful of headline markets while most listed contracts barely trade.

This repository is a free teaser, not the dataset. It holds 25 example rows and a summary table with no names in it. The full file has 99,817 rows and is sold by Tensorust LLC: https://tensorust.com/datasets/prediction-market-liquidity/.

Files here

file	what it is
sample.csv	25 rows of the full file (the same sample shown on tensorust.com)
summary_by_category.csv	row counts and totals by category across the full file, no entity names (groups with fewer than 3 rows are folded into "Other")

Summary by category (largest groups)

Category	rows	Volume (USD)
Elections	29,746	1,883,701,060
Sports	27,294	29,564,668,140
Financials	12,479	38,407,205
Crypto	9,327	1,970,365,778
Entertainment	6,639	49,717,035
Politics	3,296	5,096,948,287
Mentions	3,131	22,329,358
Economics	2,947	3,900,443,993
Commodities	1,814	5,340,050
Science and Technology	778	49,714,199
Climate and Weather	672	7,163,484
Other	582	3,518,571,811
TOTAL	99,817	50,751,085,181

Full table: summary_by_category.csv.

What the full file has

• 99,817 rows
• Key fields: platform, market_id, event_id, series, title, event_title, category, category_basis, status, result
• Parquet and CSV, a README with sources, method and limits, and the build script
• Free 25-row sample (no personal contact data)

Coverage: 99,817 markets: 95,617 Kalshi (open, closed and recently settled, newest first) and 4,200 Polymarket (the highest-volume open and closed markets: the Gamma API stops paging at about 2,100 per query). Pulled Nov 6, 2026 (Kalshi trade API v2; Polymarket Gamma API)

Columns in the full file

column	meaning
platform	Kalshi or Polymarket
market_id	Ticker or market id
event_id	Event
series	Series
title	Market question
event_title	Event title
category	Category
category_basis	exchange (Kalshi) or keyword rule (Polymarket)
status	Market status
result	Resolution, if settled
volume_usd	Lifetime volume (contracts on Kalshi, USD on Polymarket)
volume_24h_usd	Last 24 hours
open_interest	Open interest (event level on Polymarket)
liquidity_usd	Polymarket order book liquidity
best_bid	Best YES bid
best_ask	Best YES ask
spread	Ask minus bid
last_price	Last trade
bid_size	Size at best bid (Kalshi)
ask_size	Size at best ask (Kalshi)
open_time	Open
close_time	Close
created_time	Created
url	Market page

Get the full file

tier	price	includes
Snapshot file	$900	Every market in the panel plus the category rollup.
Daily panel	$750 a month	A fresh snapshot every day, building a spread and volume history per market.
Fund license	$12,000 a year	Daily panel, full history, hourly snapshots on request and use across your fund.

Email mattbusel@tensorust.com with the tier and a billing contact, and we will send a proper invoice (ACH or card). The file is delivered once the invoice is paid. Details and the live sample: https://tensorust.com/datasets/prediction-market-liquidity/. All datasets: https://tensorust.com/datasets/

Method and limits

Kalshi: page through events by status (open, closed, settled) with nested markets; category is Kalshi's own event category. Polymarket: page through markets by volume, open first, then closed (the Gamma API stops paging after about 2,100 markets per query); a keyword rule assigns a category (category_basis says which). Spread is best ask minus best bid on the YES side. A Polymarket result is recorded when one outcome's final price is 0.99 or more.

Not trading advice and not a full history of either exchange: Kalshi settled markets are the most recent pages and Polymarket open and closed markets are each the top 2,100 or so by volume. Kalshi volume is counted in contracts (each pays $1), Polymarket's in USD. One snapshot; daily snapshots build the spread history.

Sources

• Kalshi public trade API v2, /events with nested markets (https://api.elections.kalshi.com/trade-api/v2)
• Polymarket Gamma API, /markets (https://gamma-api.polymarket.com)

License

The sample and summary here are free to view, analyze and cite with attribution to "Tensorust LLC, https://tensorust.com/datasets/prediction-market-liquidity/". The full dataset is licensed separately per tier. No resale or redistribution of Tensorust data without a written license.

Tensorust LLC, Tuckahoe NY. mattbusel@tensorust.com | https://tensorust.com