01
The news
Courts and states kept pressing on sports contracts, Kalshi sought more money, and Polymarket added limits for heavy traders.
−28.5 pts
Fall in Polymarket's price for Lula winning Brazil, Sept 28 to Oct 4
Polymarket's busiest market of the week. Polls had Lula ahead; Flávio Bolsonaro took about 47% of the first-round vote to Lula's 45%.
Markets and the economy · Sun, Oct 4
Flávio Bolsonaro led Brazil's first round with about 47% of the vote to Lula's 45%
Polls had Lula ahead. Polymarket's price for a Lula win fell from 42.5% to 14% over the week; the runoff is on Oct 25.
Markets and the economy · Fri, Oct 2
US added 29,000 jobs in September as unemployment rose to 4.2%
The miss sent traders towards a Fed hold: Polymarket's price for no change on Oct 28 rose from 33.5% to 82.5% over the week.
New exchanges and products · Tue, Sep 29
Kalshi in talks to raise about $1B at a valuation near $40B, Reuters reported
Tiger Global and Dragoneer are in talks to join the round; Kalshi raised $1B at a $22B valuation in May.
Regulation · Wed, Sep 30
Ohio's governor vows to enforce gambling law against Kalshi after appeals ruling
The Sixth Circuit found on Sept 25 that Kalshi's sports contracts aren't swaps and that federal law doesn't override Ohio's or Tennessee's betting laws.
Market integrity · Tue, Sep 29
CFTC investigates Adam Kinzinger over Kalshi trades on his own pardon
The former congressman made $823 on the trades in December 2024 and January 2025; he denies wrongdoing and says he had no inside information.
New exchanges and products · Wed, Sep 30
Polymarket adds deposit limits and self-exclusion for US traders
Users can cap deposits daily, weekly or monthly and lock themselves out for 30 days, a year or for good, as pressure from regulators grows.
Regulation · Sat, Oct 3
UK urged to act as Polymarket lists contracts on HSBC and Lloyds failing
About $77,500 had traded on bank-failure contracts; a Liberal Democrat MP asked UK authorities to contact US regulators.
Culture and publicity · Thu, Oct 1
Victor Wembanyama says he will never promote betting or prediction markets
The Spurs star called it "very sad" to see players promote them, after LeBron James's reported $15M-a-year Polymarket deal.
02
The money
Kalshi's week isn't in yet. Polymarket US led the rest with $694M paid for contracts, up 1% on the week; Polymarket's international site took $513M, up 7%.
Twelve weeks of volume, exchange by exchange
July 13 to 19, 2026
$0
Dollars paid for contracts each week, from DefiLlama. Exchanges often quote notional volume, which counts every contract at $1 and is larger.
Who had the week
- Polymarket36%$513.1M
- Polymarket US49%$693.6M
- Opinion5%$71.5M
- Others10%$142.5M
Day by day
Dashed: a day an exchange hasn't reported yet.
Every exchange this week
| Exchange | Volume | vs last week | Share | Open interest |
|---|---|---|---|---|
| Polymarket US | $693.6M | +1% | 49% | $226.8M |
| Polymarket | $513.1M | +7% | 36% | $339.7M |
| Predict.fun | $75.1M | +8% | 5% | — |
| Opinion | $71.5M | +17% | 5% | $3.2M |
| XO Market | $14.1M | +75% | 1% | — |
| MagicMarkets | $12.1M | +3% | 1% | — |
| SX Bet V2 | $11M | +14% | 1% | — |
| TurboFlow Prediction Markets | $10.6M | +14% | 1% | — |
| PredictStreet | $8.6M | −39% | 1% | — |
| Polymarket Combos | $4.7M | +19% | 0% | — |
| world | $2.5M | −26% | 0% | — |
| Overtime | $2M | +35% | 0% | — |
| PancakeSwap Prediction | $1.8M | −4% | 0% | — |
| Kalshi | — | — | $1.5B |
03
The markets
Brazil's first round cut Lula from 42.5% to 14%, and a weak jobs report lifted a Fed hold in October from 33.5% to 82.5%.
Where the money went
Polymarket
Each bubble is a market, sized by what traded on it this week. Kalshi counts contracts at $1 and Polymarket the dollars paid, so compare sizes within each exchange.
What moved
Lula wins Brazil
from 43% at the start of the week
Fell from 42.5% to 14% as Flávio Bolsonaro beat the polls and led the first round with about 47%; the runoff is Oct 25
Fed holds in October
from 34% at the start of the week
Rose from 33.5% to 82.5% after September payrolls grew by just 29,000 and unemployment rose to 4.2%
Iran ceasefire holds to Oct 12
from 27% at the start of the week
Israel blames Iran for stabbing
from 44% at the start of the week
Bitcoin dips to $62.5K in Oct
from 42% at the start of the week
US confirms aliens by Oct 31
from 32% at the start of the week
04
Called it?
What each market paid for the outcome as the week began, and what happened.
Ringed: an upset. Point at a dot for the market.
05
Your call
Guess the odds, then see what traders are paying.
Polymarket
Yamal wins Ballon d'Or
You: 50%
Polymarket
US invades Iran before 2027
You: 50%
Kalshi
Georgia beat Alabama
You: 50%
06
The winners
mooseborzoii topped Polymarket's weekly profit board with $1.6M on $37.8M traded; the biggest single win was $1.2M, on Romania vs Sweden.
Most profit this week
- 4BillyGating+$616.4K
- 5fortnitethegoat667+$578.8K
- 6TeamA+$502.1K
- 7gmpm2+$481.9K
- 8anoin123+$442.9K
Biggest single wins
- +$1.2M
joseph00677 staked $1.4M, collected $2.6M
Diabolical-Prize staked $1.3M, collected $2.2M
- +$890.8K
mooseborzoii staked $1.2M, collected $2.1M
- +$744K
BreakTheBank staked $261.4K, collected $1M
- +$684.4K
BreakTheBank staked $495.4K, collected $1.2M
- +$660K
Diabolical-Prize staked $340K, collected $1M
Polymarket's public leaderboard over the seven days to collection. Names are the ones traders chose.
07
On VPX
In play money that can't be cashed out, 9 traders made 133 trades worth T$125K, up from T$10.2K the week before; a US strike on Cuba took T$99K of it.
- T$125K
- traded, +1124% on the week before
- 9
- traders
- 133
- fills
- 3
- new members
- T$750.9K
- on offer in the order books
- 265
- open markets
Volume by week, T$
Busiest on VPX
- Will US Strike Cuba in 2026?T$99.1K · 1%
- WHO declares high-fatality pandemic before 2035?T$11.6K · 20%
- AI causes 1,000+ deaths before 2030?T$9,500 · 20%
- Olivia Chow re-elected as Mayor of Toronto?T$2,800 · 45%
- Will Wealthsimple go public in 2026?T$1,300 · 40%
08
The week ahead
September US inflation figures on Oct 14, Brazil's runoff on Oct 25, the Fed's decision on Oct 28 and the US midterms on Nov 3.