TLDR
- Polymarket and Kalshi together control roughly 79% of the prediction market, with Polymarket leading on volume at $56 billion versus Kalshi’s $44 billion
- Kalshi is CFTC-regulated and legal for US users, while Polymarket operates offshore on the Polygon blockchain using USDC
- Kalshi earned $260 million in 2025, driven heavily by sports betting; Polymarket only began charging fees in early 2026
- Both Robinhood and Coinbase are building their own CFTC-licensed exchanges, which could threaten Kalshi’s distribution advantage
- Polymarket acquired prediction market API startup Dome in February 2026, signaling a push to build developer infrastructure
Polymarket and Kalshi have become the two biggest names in prediction markets. Together they control about 79% of a market that has now crossed $127 billion in total notional volume.
They could not be more different in how they operate.
Polymarket runs on the Polygon blockchain and settles trades in USDC. It has no geographic restrictions outside the United States and draws a global, crypto-native user base. Kalshi is a fully regulated US exchange holding a CFTC Designated Contract Market license, the same class of license held by major futures exchanges.
For US residents, that difference is the whole ballgame. Polymarket is blocked for US users following a $1.4 million CFTC fine in 2022. Kalshi is fully legal.
Volume and Revenue
On raw trading volume, Polymarket leads clearly. Its notional volume stands at $56 billion compared to Kalshi’s $44 billion as of February 2026. Monthly trading volume on Polymarket runs above $500 million, while Kalshi sits at roughly $50 to $80 million.
Kalshi, however, is far ahead on revenue. It brought in $260 million in 2025, up from $24 million in 2024. The NFL season alone contributed $138 million in a single quarter. Polymarket had near-zero revenue through most of 2025, only launching its taker fee system in early 2026. In its first week of fees, it generated over $1 million.
Kalshi charges roughly 7 to 12 percent of the spread on a round trip. Polymarket’s model takes around 2 percent of winnings on market orders, which works out cheaper on larger positions.
Kalshi earns 89 percent of its revenue from sports markets. Polymarket’s trading is more spread across politics and macroeconomics, where individual bets can be far larger. During the 2024 US election, one trader placed a single bet of over $50 million on Polymarket.
Channels, Infrastructure, and Competitive Threats
Kalshi has built strong retail distribution through partnerships with Robinhood and Coinbase, which together drove more than half of Kalshi’s 2025 volume. It also has real-time odds appearing on CNN and CNBC broadcasts.
Polymarket is taking a different route, building developer infrastructure rather than retail channels. In February 2026, it acquired Dome, a Y Combinator startup that provides prediction market APIs letting developers tap liquidity from multiple platforms with a single integration.
The biggest threat to Kalshi comes from those same channel partners. Robinhood and Susquehanna are building their own CFTC-licensed exchange through a joint venture to acquire MIAXdx. Coinbase is acquiring The Clearing Company to do the same. Both are expected to be operational in 2026, at which point they could stop routing volume through Kalshi entirely.
Both platforms have also been competing aggressively off-platform. In early February 2026, Kalshi offered free groceries at a New York supermarket. Polymarket responded the next day with its own free food pop-up running five days, plus a $1 million donation to the Food Bank for New York City.
As of February 2026, Polymarket’s revenue over the prior 30 days was $3.18 million according to DefiLlama data, with its revenue curve only beginning to rise in January 2026.
