- ▸ Kalshi’s $3.91B weekly volume (+27.8% WoW) vs. Polymarket’s $1.96B (+~4%) widens the gap to ~$2B.
- ▸ Kalshi now leads on both volume and transactions: 20.2M trades vs. 19.2M, reversing a 25% Polymarket transaction lead six weeks ago.
- ▸ Kalshi is 84.9% sports + exotics (with parlays at a record 10.6%), while Polymarket remains more diversified (sports just 46.3%, with politics/crypto meaningful contributors).
Weekly notional volume bounced back sharply after last week’s post-Masters pullback, with the two leading prediction markets combining for $5.9B in weekly notional volume for the week of April 20, according to DeFi Rate’s prediction markets volume tracker. Kalshi posted $3.91B, up 27.8% week over week from $3.06B, while Polymarket reached $1.96B, up ~4% WoW from $2.04B, a modest recovery compared to Kalshi’s surge.
The divergence pushed Kalshi’s volume lead over Polymarket to nearly $2B, its widest margin in recent history. Kalshi now commands 67% of combined Kalshi+Polymarket weekly notional volume. The NFL Draft (April 23–25), NBA first-round playoff action, and FOMC anticipation building into the April 28–29 meeting all contributed. Mostly, we are seeing the effects of Kalshi’s sports (and parlay) dominance driving revenue divergence in sports-heavy weeks.
Kalshi vs. Polymarket: Head to Head
Kalshi’s weekly volume is now up ~33% over six weeks ($2.93B to $3.91B) while Polymarket is down ~16% ($2.34B to $1.96B) over the same period. Kalshi continues to outpace Polymarket on a weekly basis, and has now crossed $3B in four of the last six weeks.
Kalshi vs. Polymarket Last Six Weeks (3/16 – 4/26)
| Week | Kalshi Volume ($) | Polymarket Volume ($) | Kalshi Transactions | Polymarket Transactions |
|---|---|---|---|---|
| 3/16/2026 | $3.40B | $2.54B | 21.4M | 27.4M |
| 3/23/2026 | $2.73B | $2.24B | 19.0M | 26.3M |
| 3/30/2026 | $2.90B | $1.97B | 20.1M | 22.7M |
| 4/6/2026 | $3.54B | $2.48B | 22.2M | 22.3M |
| 4/13/2026 | $3.06B | $2.04B | 20.9M | 21.4M |
| 4/20/2026 | $3.91B | $1.96B | 20.2M | 19.2M |
The last time Polymarket’s notional volume edged out Kalshi was the week of Oct. 13, 2025 when totals were $1.06B to $950.4M, according to Dune tracking. Just two months earlier, in the week of Jan. 26, the volume difference between the two was just $112.3M.
On transactions, Kalshi edged ahead for the first time in the tracked period with 20.2M to Polymarket’s 19.2M. Six weeks ago, Polymarket held a 25% transaction lead. The reversal marks a notable shift: Kalshi is now winning on both volume and trade count, though the two remain close on transactions.
Kalshi categories and key volume drivers
Kalshi’s sports + exotics combined came in at $3.32B (84.9% of total), up from $2.52B the prior week. Exotics (Kalshi “combos” that function like parlays) hit a new high of $412.5M, making up 10.6% of Kalshi’s total volume and surpassing Crypto ($330.2M, 8.5%) as the No. 2 category for the second straight week. Crypto itself was flat WoW, going from $330.1M to $330.2M. Politics ticked up to $35.6M while Economics ($7.7M) and Mentions ($12.9M) remained steady.
Kalshi Category Breakdown: Week of April 20
Other includes: Science and Technology ($3.8M), Companies ($2.0M), Social ($522K), World ($311K), and Other ($94K).
Exotics (parlays) becoming a Kalshi staple
Exotics’ 10.6% share last week was second only to college basketball championship week (March 2), since Dune began tracking the category in late February. That’s up from $266M (8.7%) the prior week and nearly triple the $152M (5.6%) recorded the week of February 23. The category has held above 7.5% every week since early March, with this week’s surge, driven by NBA playoff parlays and NFL Draft combo markets, pushing it to a new peak in both dollar terms and share of total volume. Exotics is beginning to regularly outpace Crypto as Kalshi’s #2 category.
Kalshi Exotics Category Over Time (Thru April 26)
Kalshi’s volume leaderboard this week was headlined by NBA playoffs, according to DeFi Rate volume tracking. The Pro Basketball Champion market (OKC Thunder leading at 53%) topped the chart at $5.4M weekly volume but $74.9M open interest, the single largest open interest (OI) position on the platform. Stanley Cup Champion ($23.2M OI), 2028 Democratic Presidential Nominee ($67.1M OI), and Pro Baseball Champion ($11.3M OI) round out the high-OI markets. The Fed decision in April is essentially locked (maintain rate at over 99%), but still generated $1.1M in weekly volume and $14.3M in open interest.
Polymarket category breakdown and key volume drivers
Polymarket’s category mix was headlined by a Trump market revival, surging to $222.5M (11.3% of volume) after collapsing to $95.9M the prior week, more than doubling WoW as short-dated Trump speech and news markets regained traction. Sports held the top slot at $908M (46.3%), led by the 2026 FIFA World Cup Winner market ($71M all-time volume, France leading at 17%) and NBA championship betting. Crypto came in at $429M (21.8%), rebounding solidly from the prior week. Politics reached $298M (15.2%), sustained by 2028 nominee markets (led by Newsom, Vance) and the Peru presidential race. Weather ($42.5M), Culture ($24.2M), Economy ($19.1M), and Tech ($16.8M) rounded out the mid-tier, with Tech buoyed in part by weekly Elon Musk tweet-count markets.
The contrast with Kalshi remains stark: Polymarket’s volume is spread across a much broader category mix, while Kalshi is increasingly concentrated in Sports and Exotics, with those two categories alone accounting for 84.9% of Kalshi’s total last week compared to 46.3% sports share for Polymarket.
Polymarket Category Breakdown: Week of April 20
Fees and platform snapshot
Polymarket fees increased ~14% WoW to $8.11M for the week (up from $7.13M the prior week), with Polymarket capturing the vast majority of tracked fee revenue. The DeFi Rate weekly snapshot for the week of April 20 shows combined metrics across the sector: $5.9B weekly notional volume, 358,963 active markets (Kalshi 311,234 / Polymarket 46,790), 39.4M transactions, and $1.1B open interest (Kalshi $610.8M / Polymarket $509.5M).
Trading events to watch
As April comes to a close, the sports calendar is only heating up which is good news for combos and sports volume at Kalshi. NBA and NHL playoffs are underway, and the World Cup is quickly approaching. The FOMC decision market will soon close, but trading will soon spike again for the next fed rate decision June 16-17. Election trading interest is also already on the rise, not just for 2026 midterm markets but also for the 2028 presidential election. And another election in Peru is gaining serious interest among traders, especially on the international Polymarket platform.
Markets we’re watching:
- FOMC decision (April 28–29): Markets are locked at 99–100% for no change, but high open interest on both platforms means a surprise would move volume sharply.
- NBA playoffs: Multiple first-round series in progress; OKC Thunder leads both Kalshi and Polymarket champion markets at 53%.
- 2026 FIFA World Cup (July): Already Polymarket’s #2 active market by volume at $71M; will continue to build.
- Peru Presidential Election (June 6): Keiko Fujimori leading at 63% on Polymarket ($8.6M volume, $2.8M OI); active on Kalshi as well.
- 2028 presidential nominee markets: Gavin Newsom (26% Polymarket, 25% Kalshi) and JD Vance (39% Polymarket, 38% Kalshi) are among the highest open-interest markets on both platforms.
Expect Kalshi to maintain a sizable lead over Polymarket through the NBA playoffs, at least, with a $4B week well within reach for the volume-leading prediction market platform.
