- ▸ Kalshi ($3.06B) and Polymarket ($2.04B) both pulled back after record highs for week of April 13, mainly due to a lighter sports and political calendar.
- ▸ Kalshi attracts fewer, larger bets (~$147 avg), while Polymarket sees more smaller bets (~$95 avg), with transaction counts converging.
- ▸ Sports dominated Kalshi again; Polymarket had a more balanced mix, with Trump-related markets collapsing but other political and tech markets rising.
Weekly notional volume on the two largest prediction markets pulled back from the prior week’s Masters-fueled highs. Kalshi posted $3.06B for the week of April 13, down 13.6% WoW from the prior week’s record $3.54B. Polymarket had $2.04B in notional volume last week, down 17.5% from $2.48B, according to DeFi Rate’s prediction markets volume tracker. Between the two, the week saw roughly $914M less in weekly volume, which ebbs and flows with the sports calendar and political forces.
The decline follows record numbers for the sector. Kalshi set an all-time record over $3.5B during Masters week as Polymarket’s Trump markets doubled. With no comparable golf major this week, the NBA regular season wrapping up, and no breaking geopolitical catalyst, both venues reverted toward baseline. Kalshi’s roughly $1B lead over Polymarket held steady, consistent with the gap we flagged earlier this month.
Kalshi vs. Polymarket head to head
Over the past six weeks, Kalshi’s weekly volume is up ~4% ($2.93B → $3.06B) while Polymarket’s is down ~13% ($2.34B → $2.04B). Kalshi has outpaced in every single week and is on a two-week streak for $3B-plus, which is starting to feel like the platform’s new baseline.
Kalshi vs. Polymarket Last 6 Weeks (March 9 – April 19)
| Week | Kalshi Volume ($) | Polymarket Volume ($) | Kalshi Transactions | Polymarket Transactions |
|---|---|---|---|---|
| 2026-03-09 | $2.93B | $2.34B | 19.7M | 24.7M |
| 2026-03-16 | $3.40B | $2.54B | 21.4M | 27.4M |
| 2026-03-23 | $2.73B | $2.24B | 19.0M | 26.3M |
| 2026-03-30 | $2.90B | $1.97B | 20.1M | 22.7M |
| 2026-04-06 | $3.54B | $2.48B | 22.2M | 22.3M |
| 2026-04-13 | $3.06B | $2.04B | 20.9M | 21.4M |
On transactions, Polymarket still edges Kalshi (21.4M vs. 20.9M this week), but the lead has nearly vanished. Polymarket was 25% ahead on transactions in the week of March 9; the gap has now compressed to ~3% as Polymarket’s transaction count dropped ~13% over six weeks while Kalshi’s rose ~6%.
This week’s pullback was concentrated in number of contracts traded (because these volume figures reflect notional volume), not usage. Kalshi volume fell 13.6% WoW against a 5.8% transaction decline. Polymarket volume fell 17.5% against just 4.1% fewer transactions. Translation: users stayed engaged but were buying fewer contracts compared to an inflated Masters week that had additional Iran-related geopolitical catalysts on the Polymarket side.
Category mix for Kalshi and Polymarket
Kalshi’s sports + exotics (combos AKA parlays) dropped from $3.04B to $2.52B WoW, putting the combined sports volume at 82.5% of last week’s total, down from 85.8% for the peak Masters week. Crypto trading was the only major category in the green (+11.5% to $330M). Politics (−23.7%), Mentions (−37%), and Economics (−58%) all dropped.
Kalshi’s volume leaderboard last week was dominated by NBA with the play-in tournament running (April 14-18) and playoffs tipping off April 18. Pro Basketball Champion, MVP, Rookie of the Year, Stanley Cup, and multiple first-round playoff series accounted for most of the top 20. Notable non-sports entries included the California gubernatorial race, the 2028 Democratic nominee market, and a Trump mention market at a Turning Point USA Phoenix event that resolved April 18.
Kalshi Category Breakdown: Week of April 13
| Category | Apr 13 | % of Total |
|---|---|---|
| Sports | $2,255,881,078 | 73.70% |
| Crypto | $330,123,795 | 10.80% |
| Exotics | $266,153,441 | 8.70% |
| Unknown | $110,526,636 | 3.60% |
| Politics | $29,146,751 | 1.00% |
| Climate and Weather | $15,042,301 | 0.50% |
| Financials | $13,522,890 | 0.40% |
| Mentions | $13,306,801 | 0.40% |
| Economics | $8,336,763 | 0.30% |
| Other | $16,989,570 | 0.60% |
| Total | $3,059,030,026 |
Polymarket ran a more balanced mix. Sports held the top slot at $944M (−9.6% WoW), led by the 2026 FIFA World Cup winner and Champions League quarterfinal ties (Liverpool–PSG, Bayern–Real Madrid). The headline move was the Trump category collapsing −80.4% WoW ($488M → $96M) as short-dated Trump-speech markets wound down and attention rotated into the broader Politics category, which rose 22.8% to $435M on 2028 nominee markets (Newsom, Vance) and the Peru presidential race. Crypto slipped 6.3% to $445M but remained a solid No. 2. Tech was the only Polymarket category to post a clean gain (+47%), in part on a surge in weekly Elon Musk tweet-count markets.
Polymarket Category Breakdown: Week of April 13
| Category | Apr 13 | % of Total |
|---|---|---|
| Sports | $944,222,957 | 46.20% |
| Crypto | $444,724,432 | 21.80% |
| Politics | $434,893,495 | 21.30% |
| Trump | $95,935,804 | 4.70% |
| Weather | $48,129,594 | 2.40% |
| Economy | $33,331,857 | 1.60% |
| Culture | $25,916,397 | 1.30% |
| Tech | $11,900,069 | 0.60% |
| Other | $2,805,820 | 0.10% |
| Total | $2,041,860,425 |
Polymarket fees and cross-platform comparison
Polymarket fees eased 8.2% WoW to $7.13M after peaking at $7.77M the prior week. Polymarket has captured ~95%+ of tracked fees for three straight weeks, but Kalshi’s fees are not included in the tracking. Fees held up better than volume, consistent with a richer mix of higher-fee markets.
Polymarket Fees Last 4 Weeks
| Week Start | Polymarket Fees | Total Fees (All Platforms) | PM Share |
|---|---|---|---|
| Mar 23 | $2.23M | $2.50M | 89.20% |
| Mar 30 | $6.27M | $6.45M | 97.20% |
| Apr 6 | $7.77M | $8.07M | 96.30% |
| Apr 13 | $7.13M | $7.50M | 95.10% |
Most smaller tracked platforms saw week over week increases, according to Dune’s cross-platform tracking. predict.fun surged from $117M to $702M, Opinion grew 83% to $216M, and Limitless rose 49% to $91M. Kalshi + Polymarket’s combined share of tracked volume slipped from 92.5% to 81.2% WoW, though Dune notes there is no filter for wash volume applied, so interpret those numbers with caution.
What to watch this week
This week, we have a big volume driver in the NFL Draft, the next fed rate decision dropping soon, NFL playoffs in full force, and also World Cup lead-up and US primary election races heating up. Here’s an overview of some major trading events coming up:
- NFL Draft (Thu–Sat, Apr 23–25): a historically strong driver for Kalshi’s event book via pick-position, team-specific, and over/under markets; Polymarket typically mirrors the slate.
- FOMC decision (Apr 28–29): Fed-rate markets are already top-20 on both venues; Polymarket’s “no change” contract is near 99%, but volume typically builds into the print.
- NBA 1st-round playoffs: multiple series markets already among Kalshi’s top 20; Polymarket’s 2026 NBA Champion market is the platform’s No. 4 by volume.
- Champions League semifinals (late April–early May) and the Eurovision final (May 16): sustained drivers of Polymarket’s sports and culture categories.
- Peru presidential election (Jun 6): Fujimori leading with rising volume on both platforms.
After the expected post-Masters weekly volume dip, don’t expect additional regression in the coming weeks. There’s plenty of interesting events to help sustain and exceed current volume levels, and we will soon see if Kalshi’s new $3B baseline holds.
Note: Notional volume counts each contract at its $1 max payout, not its trade price.
