Kalshi's $170 Billion Market Is Being Driven by Traders Under 35

Kalshi's total trading volume surpassed $170 billion year-to-date by August 2026, and more than 60% of participants on the platform and its rival Polymarket are under 35, according to a survey from S&P Global Market Intelligence's Kagan unit. The numbers frame a generational shift in speculative finance: young adults are treating event contracts — on weather, politics and sports — as a side hustle rather than a novelty bet.

The youngest cohort is moving serious money. Traders aged 18 to 21 were responsible for roughly $5.4 billion in trading activity on Kalshi through August 2026, CNN reported. That is a slice of the $170 billion total, but a meaningful one, and it has pushed the company to add consumer-protection guardrails aimed squarely at its youngest customers.

What are these users actually trading?

Sports contracts ranked as the favorite category among younger users, the Kagan survey found. But the menu goes well beyond scoreboards. Kalshi lists contracts on questions like who will become President Donald Trump's next press secretary and when NASA will next put astronauts on the moon.

Each contract works as a yes-or-no question with a price attached. If a trader thinks the market is underestimating the odds, they buy. If the event happens, they get paid. If it doesn't, the stake is gone.

Thomas Carvo, a 28-year-old who studied meteorology, represents one distinct archetype. He puts his training to work trading contracts on tomorrow's weather in various cities, leaning on specialized knowledge most of the market lacks. He has also profited from contracts tied to the 2024 Trump election. Carvo frames his approach as a long-term commitment rather than a quick score — a deliberate contrast with the impulse-driven trading that has raised concern among regulators and safety advocates.

What guardrails has Kalshi added?

The surge in young users has raised red flags about addiction and financial losses. Kalshi has responded with a handful of safeguards:

• On October 27, 2026, the company introduced a default monthly deposit limit of $2,500 for traders aged 18 to 20.
• It has partnered with youth safety organizations to promote responsible trading habits.

The deposits cap matters operationally: it constrains how much capital the youngest, least experienced segment can deploy each month, trimming downside risk for users and, by extension, reputational exposure for the exchange.

Kalshi built its business as a prediction market regulated by the Commodity Futures Trading Commission, the federal agency that oversees futures and derivatives. Its model centers on regulated event contracts settled in dollars — a traditional cash setup.

How does Polymarket differ?

Polymarket, Kalshi's main rival, runs on different rails entirely. It operates on blockchain and uses pUSD, an ERC-20 token backed by the USDC stablecoin, as collateral for trades. ERC-20 is the standard token format on Ethereum; USDC is a dollar-pegged stablecoin designed to hold a one-to-one value with the dollar. Polymarket users are still betting in dollar terms — just with crypto plumbing underneath.

That structural split carries regulatory weight. Kalshi sits squarely inside the CFTC's oversight perimeter with dollar-settled contracts, while Polymarket's token-collateralized model occupies a grayer zone that has drawn scrutiny from US authorities. The demographic data suggests both venues are competing for the same under-35 audience, but under materially different compliance regimes.

The deposit-limit experiment will be the thing to watch: if voluntary caps on 18-to-20-year-olds fail to curb problem trading, pressure for harder regulatory limits on event-contract access for young users is likely to grow.