Polymarket has appointed Warren Jenson, a former chief financial officer of Amazon, as its first chief financial officer. The company announced the appointment on Thursday, September 10, as it works to narrow a substantial volume gap with rival prediction-market operator Kalshi.

Jenson will report to Polymarket founder and CEO Shayne Coplan. His responsibilities will include capital strategy, long-range planning, and financial infrastructure. The appointment was announced in a company release.

An executive with experience at major companies

Before joining Polymarket, Jenson served as president and CFO at Nielsen and as president at LiveRamp. Earlier in his career, he was CFO at Amazon, Electronic Arts, Delta Air Lines, and NBC.

Jenson holds accounting degrees from Brigham Young University and serves on the boards of DigitalOcean, Dropbox, and Ripple.

“We’re assembling the team to match the opportunity in front of us,” Coplan said in the announcement.

Jenson said that “Polymarket created a massive new global market category.” He added that he was joining “the leadership team to put the capital strategy and operating discipline in place to move quickly at scale and continue to push the frontier of this industry.”

Kalshi maintains a large volume lead

Kalshi and Polymarket are the two leading prediction-market platforms, but Kalshi remains significantly ahead in trading volume. At the end of June, Kalshi recorded approximately $33 billion in volume, compared with $14.5 billion for Polymarket.

Combined, the two platforms processed about $47.5 billion that month—more than three times the roughly $14 billion that US sportsbooks averaged per month in 2025, according to Pew Research figures.

More recent activity shows a similar gap. Data from DefiLlama indicates that prediction markets generated approximately $4.05 billion in volume over the previous seven days. Polymarket accounted for roughly $922 million of that volume and about $4.06 million in revenue, while Kalshi recorded $2.91 billion in volume during the same period.

Polymarket is generally cheaper to trade and does not charge makers, but it has not matched Kalshi’s headline volume figures. A comparison of the two platforms outlines additional differences between their models. The figures make volume, pricing, and operating structure the main measurable points of comparison as Polymarket seeks to close the gap.

Regulation is another area of competition

Polymarket may have a potential advantage in regulatory proceedings. Kalshi is a CFTC-regulated exchange and argues that federal derivatives law gives the commission exclusive jurisdiction. Several states dispute that position.

According to Cryptopolitan’s reporting, Washington, Massachusetts, Michigan, Nevada, and New York have all taken action against Kalshi. New York’s lawsuit seeks more than $36 billion in damages.

A Michigan judge ordered Kalshi to withdraw its sports contracts and threatened a penalty of up to $500,000 per day. New Jersey has also asked the Supreme Court to resolve which authority governs these markets.

Polymarket established a US foothold by acquiring CFTC-licensed QCX. The acquisition gave it a regulated domestic arm that operates separately from its geo-blocked international platform.

Jenson’s mandate includes building financial systems capable of supporting both operations under two substantially different regulatory frameworks. That places the CFO role at the intersection of Polymarket’s volume challenge and its effort to maintain separate domestic and international operations. The appointment places capital strategy, planning, and financial infrastructure at the center of Polymarket’s effort to compete with Kalshi.