Updated October 27, 2026. Prediction market volume is heavily concentrated this week, with three macro catalysts drawing the overwhelming share of liquidity across Kalshi and Polymarket. The November 4–5 FOMC decision, the 2026 Senate control contracts, and year-end Bitcoin price markets are each clearing multi-million-dollar daily turnover. Below is where the smart money is positioned, what the odds imply, and the setups worth watching.
Top 10 Contracts by Weekly Volume
The table below ranks the ten highest-volume prediction contracts across Kalshi and Polymarket for the week ending October 26, 2026. Volume is approximate seven-day notional in US dollars.
| Rank | Contract | Platform | Current Odds | 7-Day Volume |
|---|---|---|---|---|
| 1 | Fed cuts rates at November FOMC | Kalshi | 71% Yes | $18.4M |
| 2 | Democrats win Senate majority 2026 | Polymarket | 44% | $14.9M |
| 3 | Bitcoin above $115K on Dec 31, 2026 | Polymarket | 58% | $11.2M |
| 4 | Q4 2026 US GDP above 2.0% | Kalshi | 63% Yes | $7.8M |
| 5 | Ethereum above $4K on Dec 31, 2026 | Polymarket | 51% | $6.3M |
| 6 | Georgia Senate: Republican wins | Kalshi | 52% Yes | $5.9M |
| 7 | CPI November YoY above 2.8% | Kalshi | 38% Yes | $4.7M |
| 8 | Government shutdown before Dec 15 | Polymarket | 22% | $4.1M |
| 9 | Ohio Senate: Democrat wins | Polymarket | 46% | $3.8M |
| 10 | S&P 500 closes above 6,000 in 2026 | Kalshi | 67% Yes | $3.4M |
Three themes jump out of the leaderboard: rate-cut positioning dominates macro flow, Senate contracts are tightening as early-vote data trickles in, and crypto year-end strikes are drawing the largest Polymarket volume since the summer.
Macro: The Fed Dominates the Order Book
Kalshi’s November FOMC contract is this week’s single largest market, with Yes trading at 71% for a 25 basis point cut and 8% for a 50 basis point cut. The combined 79% probability of some easing is roughly in line with fed funds futures, but prediction market positioning has been noticeably steadier through the week than the rates complex, which chopped on Monday’s PPI surprise.
The companion CPI contract is the more interesting setup. Kalshi lists “November CPI YoY above 2.8%” at 38% Yes. That is a meaningful markdown from early-October levels near 48% and reflects the recent run of softer services-ex-housing prints. A hotter-than-expected release on November 13 would reprice both this contract and the December FOMC market, where current odds imply a 54% chance of a second consecutive cut.
Q4 GDP tracking contracts are also drawing institutional-sized flow. Kalshi’s “Q4 US GDP above 2.0%” at 63% Yes has roughly doubled its open interest over the last ten days as the Atlanta Fed nowcast has drifted higher.
Politics: Senate Control Is the Tightest It Has Been All Cycle
With one week until Election Day, Polymarket’s “Democrats win Senate majority” contract is pricing at 44%, up from 39% a week ago. The move has been driven almost entirely by Ohio and Pennsylvania repricing, where state-level contracts tightened by three to five points on the back of early-vote returns.
Kalshi’s Georgia Senate market remains the single most-traded state race, with the Republican at 52% Yes. That contract has traded in a tight 48%–54% band for three weeks, which is unusual given typical late-cycle volatility. Traders should note that Kalshi’s political event contracts are the only CFTC-regulated venue for these markets in the US, and liquidity on Kalshi’s Senate book is now roughly 2.3x Polymarket’s for the same race.
The sleeper is the government shutdown contract. Polymarket has “Shutdown before December 15” at 22%, a notable discount to Washington betting markets and roughly half of what the same contract priced in early October before the continuing resolution extension was agreed in principle. If appropriations talks slip, this contract has clear repricing upside.
Crypto: Year-End Strike Markets Draw the Biggest Books
Polymarket’s Bitcoin year-end markets are the single largest crypto prediction contracts in the world right now. “BTC above $115K on Dec 31” is trading at 58%, with the full ladder (above $110K at 71%, above $120K at 42%, above $130K at 19%) pricing an implied distribution that is roughly 4–6% below listed options markets on Deribit. That spread has drawn significant arbitrage flow.
Ethereum’s year-end $4K market is a near coin-flip at 51% and has been one of the most whipsawed contracts of the quarter, moving six points in either direction on single-day Bitcoin moves. For traders using prediction markets to express views on relative crypto performance, the ETH-BTC pair of year-end contracts offers one of the cleanest expressions available on-chain.
The S&P 500 “closes above 6,000 in 2026” contract on Kalshi is also drawing crypto-adjacent flow as a macro hedge. At 67% Yes, it has traded in near-lockstep with Bitcoin year-end strikes over the last month, highlighting how prediction markets increasingly reflect the correlation structure between risk assets rather than their idiosyncratic drivers.
What to Watch Through the Weekend
Three events are likely to reprice the top of this week’s volume board. First, the Thursday Q3 GDP advance release will directly impact the Kalshi Q4 GDP contract and indirectly feed into the FOMC book. Second, final weekend early-vote data from Georgia and Pennsylvania will move the Senate contracts, with Kalshi’s state books likely to tighten further. Third, Friday’s Core PCE print is the Fed’s preferred inflation gauge; a surprise in either direction will immediately reprice the November and December FOMC markets.
Traders looking for low-correlation exposure should note that volume outside the top 10 is sparse this week. Sports contracts are quieter than usual as NFL moneyline markets have tightened to minimal edge, and legal-category contracts are flat ahead of the Supreme Court’s November arguments calendar.
Where to Trade
Both platforms on this week’s leaderboard are accessible to US traders in most states. Kalshi is the CFTC-regulated venue and is the only legal option for US residents trading political event contracts. Polymarket offers deeper books on crypto and international contracts, with settlement in USDC on Polygon.
For a side-by-side breakdown of fees, liquidity, and available markets, see our updated best prediction markets rankings, refreshed weekly.