Polymarket says it has investigated dozens of midterm bets and sent at least two cases to the CFTC
A week before the midterms, Polymarket’s head of investigations says her 16-person team has looked into dozens of suspicious election bets, and at least two cases have gone to the CFTC. How its surveillance works, what it watches for, how big the election markets are, and the odds they show.
In this article
Polymarket says it is watching its election markets for insider trading and manipulation, and has already referred cases to regulators. Shana Bautista, the company's head of global intelligence and investigations and a former FBI official, told NPR that her team has investigated "dozens" of bets on the 3 November midterms. A person familiar with the probes said at least two cases had been referred to the Commodity Futures Trading Commission.
"There's never been a case that we work where we haven't been able to identify, potentially, who these people are," Bautista said. Her warning to would-be insiders: "If you decide that you are smarter and can do it, we will find you."
Reported by NPR on 27 October 2026, as relayed by Bitcoin.com and Cryptopolitan; Polymarket announced its election surveillance system the same morning.
How the surveillance works
- The team: 16 people under Bautista, who joined in June.
- The alerts: "hundreds" a day. Trading that crosses internal thresholds goes straight to Bautista's phone.
- What it looks for: sudden concentrated bursts of trading, several accounts behaving alike, and shared device identifiers.
- What it checks against: social media, FEC filings, banking partners, crypto records and statistical models. On Polymarket US, the CFTC-regulated exchange, detection also uses verified identities, dollar funding links and order-book data, according to Polymarket's announcement.
Polymarket says it has referred more than 100 cases across all kinds of markets to law enforcement before.
Two platforms, two levels of scrutiny
Polymarket now runs two exchanges. Polymarket US is designated by the CFTC and checks every customer's identity. The larger international platform settles in crypto and lets traders take part without disclosing who they are, which is where most insider-trading worries have centred (who owns Polymarket; is Polymarket legal in the US?).
How big the election markets are
Polymarket lists 506 election markets. The biggest:
Source: Polymarket via Bitcoin.com, 27 October 2026
Show the dataHide the data
| Value | |
|---|---|
| House control | $24M |
| Senate control | $9M |
| Texas Senate | $7M |
| Michigan Senate | $3M |
| Maine Senate | $3M |
| Ohio Senate | $2M |
| Alaska Senate | $2M |
Money is concentrated: a Dune analysis found 24,930 Polymarket wallets held midterm positions on 18 October, with a median position of just $14, while the top 100 wallets held 56% of the value. Across both platforms, more than $1.4 billion has been traded on 2026 midterm markets, most of it on Kalshi (who is trading the midterms).
The odds those markets show
| Market | Polymarket, 27 October |
|---|---|
| Democrats win the House | 91.5% |
| Democrats win the Senate | 66.5% |
| Democratic sweep of both | 65.5% |
| Texas Senate: Talarico (D) | 67.5% |
| Michigan Senate: El-Sayed (D) | 68.5% |
| Ohio Senate: Brown (D) | 70.5% |
Live prices: House · Senate · our midterms hub.
Why it matters
Regulators are already acting on insider trading in prediction markets. The CFTC has ordered a former White House teleprompter operator, Gabriel Perez, to return $107,539 and pay a $65,000 penalty, and former congressman George Santos to return $17,570 and pay $17,500, with three-year trading bans for both. Kalshi has suspended six 2026 candidates for trading on their own races (insider trading on Kalshi and Polymarket).
Critics worry about more than profits. Barnard College economist Rajiv Sethi told NPR that election prices can sway fundraising and voters' sense of who is winning, warning that markets risk becoming "a self-fulfilling prophecy" (political donations from prediction markets).
