Liquidity Rewards: Polymarket Offers $150,000 a Day; Kalshi Paid $2.95M in 30 Days

Both large prediction markets pay traders to keep their order books full, but they pay in different shapes. Vultax read every reward listed by each venue's public API late on 13 September 2026. Polymarket posted liquidity rewards on 17,866 markets worth $149,859 a day, paid daily to makers whose resting orders sit near the midpoint. Kalshi attaches a reward pool to one market for a set period; programs that ended in the 30 days to 12 September and were marked paid out carried $2,952,042, about $98,000 a day.

Neither venue puts the money where trading is heaviest. On Polymarket, finance and weather markets took 27.3% of daily rewards on 5.9% of the day's volume, while esports took 0.6% of rewards on 5.5% of volume. On Kalshi the median pool was $20, and the largest series in the period was a 15-minute crypto race. Rewards sit on markets that trade little on their own, and the typical reward is small and shared among everyone quoting.

Polymarket: Vultax read the order book's current-rewards endpoint at 23:57 UTC on 13 September 2026. It lists each rewarded market's daily rate, maximum qualifying spread and minimum order size. The markets were matched to every open event on Polymarket's Gamma API, read between 00:01 and 00:03 UTC on 14 September, for tags, 24-hour volume and quoted spread. Categories are Vultax's grouping of Polymarket's tags; a market with several tags takes the first of esports, crypto, sports, politics, geopolitics, economy, finance, tech, weather and science, and up-or-down crypto markets are counted on their own.

Kalshi: Vultax read the incentive-programs endpoint at 23:57 UTC on 13 September: 207,407 programs, the earliest beginning on 18 September 2025, each with its market, dates, pool and whether it had been paid out. Kalshi reports pools in centi-cents; the figures here are in dollars. Categories come from Kalshi's own series list. Monthly and 30-day totals count programs by the date they ended and include only those marked paid out.

Polymarket's rewards reach about one open market in ten: 17,860 of 185,959 markets open for trading carried one. Most are small. The median rewarded market offered $3 a day in total, 79% offered $5 or less, and 882 offered $50 or more. The largest on the day were a market on whether the Clarity Act becomes law in 2026, at $2,502 a day, the two leading September Fed outcomes at about $1,000 each, and two markets on Sweden's next prime minister, for Ulf Kristersson and Magdalena Andersson, at $1,000 each.

Politics and sports took half of the money, well below their three-quarters of the day's trading. Finance and weather took more than a quarter on less than 6% of volume, about $14 to $22 of rewards for every $1,000 traded, against $2 to $3 in politics, sports and crypto and 42 cents in esports.

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Kalshi's programs have grown quickly. Pools paid out on programs that ended in October 2025 came to $198,545; in August 2026 they came to $2,473,663. Most programs are short and small. Over the 30 days to 12 September, 53,781 programs on 1,058 series paid out, half of them with a pool of $20 or less, and the four Sundays averaged $263,740 against $72,965 on other days. Since the earliest program in the data, 187,690 programs marked paid out have carried $12,065,409.

The mix moves from month to month. Economics led the 30 days with 26.8%, 60% of it on gas and diesel price markets, and the largest single series were a 15-minute crypto race at $180,340 and table-tennis matches at $152,100. Sports took 8.4%, 62% of it those table-tennis programs, although sports held 43.6% of Kalshi's open contracts in Vultax's open-interest reading. In August as a calendar month, weather led instead, at 19.2%.

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The two venues publish different things, so their totals are not added together here. Polymarket posts a daily amount per market and shares it among qualifying makers by a published score. Kalshi posts a pool for each program and reports whether it has been paid out.

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Four points follow from the listings themselves.

• A reward is shared, not paid per order - Polymarket splits each market's daily amount by each maker's share of the score, so a $3-a-day market pays $3 in total to everyone quoting it.
• Rewarded markets were not the tight ones - among sports markets with under $1,000 of 24-hour volume, rewarded markets had a median quoted spread of 28.4 cents against 2.0 cents for the rest; in politics, 3.0 cents against 1.0. Read it as where rewards sit, not as their effect.
• Rewards turn over daily - 59% of Polymarket's reward settings, 10,509 of 17,866, had started on 13 September, the day of the reading.
• Kalshi's money arrives in many small pieces - half of the 30 days' paid-out programs carried $20 or less, and the three largest series were a 15-minute crypto race, table-tennis matches and hourly Miami temperature.

A reward listing shows where a venue is paying for liquidity, which is often where a book is thin. The depth study shows what thin means in dollars for esports and NFL books, and the arbitrage study shows how fees decide whether a quoted gap is worth taking. Vultax's prediction-market desk follows books, spreads and depth on both venues.

One reading of each venue's reward data on 13–14 September 2026. Polymarket's daily amounts are offers: what makers receive depends on who else quotes and on the $1 minimum. Kalshi's pools are counted when a program is marked paid out; 3,480 programs that ended in August, with $184,815 in pools, were not marked paid out at the reading. Quoted spreads come from Polymarket's Gamma API and can lag the order book. Polymarket figures cover its international exchange. Nothing here is a recommendation to trade. Challenge a figure at [email protected]; material changes are logged in the changelog.