Polymarket's annualized revenue has surpassed $1.8 billion, the company told CNBC on Tuesday, nearly doubling a run rate that stood above $1 billion in June.

The growth comes almost entirely from the company's U.S. exchange, a standalone domestic marketplace that operates independently of Polymarket's international DeFi platform. The exchange opened to the American public earlier this year and has scaled at a pace that few consumer trading platforms have matched.

The volume figures explain the revenue jump. In October, the U.S. exchange processed notional volume of more than $14.5 billion, up from $4 billion in June — a more than threefold increase in four months, according to CNBC, citing TickerTracker data. That works out to roughly $470 million in matched trading value per day during October.

What is driving the trading surge?

CNBC attributed the volume growth to high-traffic sporting and news events, including the summer's FIFA World Cup and the NFL season kickoff in September. Both events drew large audiences of casual bettors into prediction markets.

Product design is doing part of the work. Combo event contracts — which function much like sportsbook parlays, bundling several legs into a single position — accounted for more than 70% of the platform's trading activity on Sunday, according to CNBC. The figure signals that Polymarket is competing directly with sportsbooks for recreational wagering dollars rather than positioning itself purely as a hedging or forecasting tool.

The company's trajectory since opening domestically has been steep:

• December: U.S. exchange debuts in a restricted period with limited access
• Mid-May: Polymarket removes the waitlist for mobile app users, widening access
• June: annualized revenue passes $1 billion, six weeks after full public opening
• October: monthly notional volume exceeds $14.5 billion
• This week: annualized revenue tops $1.8 billion

What does the new funding round signal?

Polymarket has begun raising $1 billion in new capital, a round that values the company at $21 billion, according to CNBC. The valuation places the prediction market operator among the most richly priced private fintech companies, and the raise itself — roughly one-eighteenth of the valuation — gives it fresh capital to expand while revenue compounds.

The pitch to investors is straightforward: a domestic exchange that went from zero to more than $14.5 billion in monthly notional volume inside a year, with annualized revenue that has grown by roughly $800 million since June.

Can the company outrun its regulators?

Growth has not removed the risk. The Commodity Futures Trading Commission is conducting a wide-ranging investigation of Polymarket, examining its advertising practices and whether the company breached an earlier settlement that required it to keep U.S. residents off its international exchange, according to CNBC.

Political exposure compounds the regulatory one. CNBC reported that Polymarket could face heavier scrutiny under a Democratic Congress, in part because Donald Trump Jr., the son of President Donald Trump, advises the company. A change in control of either chamber would alter the committee math that currently favors a light-touch approach to prediction markets.

The company is taking a cooperative public posture. A Polymarket spokesperson told CNBC the company intends to work with legislators as they learn the prediction market industry. "We welcome scrutiny," the spokesperson said.

The $21 billion question is whether that welcome survives contact with a CFTC investigation and a potentially hostile Congress.