In March 2026, the value traded in same-day-expiry S&P 500 options reached nearly $57 trillion. Let that number sit. One in three listed options in the United States now expires the day it is bought, and nearly half of retail options volume at Citadel Securities is in these zero-day contracts. We have built a casino inside the equity market and handed the chips to retail traders who mostly call it investing.
The mechanics of a slot machine
A 0DTE option is a lottery ticket with a stock ticker. It expires in hours, its value is dominated by gamma and time decay, and the payoff distribution is closer to roulette than to owning a business. Retail investors are the majority of participants in the S&P 0DTE market, which now accounts for over half of total S&P options volume. This is not capital formation. It is speculation at industrial scale.
The blurring goes further than options
The same impulse is metastasizing across products. Prediction markets like Kalshi and Polymarket have already cleared roughly $60 billion in 2026 volume, surpassing all of 2025, with projections of $240 billion this year. A Northwestern Mutual study found nearly a third of Gen Z and almost a quarter of millennials are putting money into prediction markets or sports betting. The wallet does not distinguish between a parlay and a same-day put.
- Selection bias in the marketing: platforms advertise the winners; the house edge and decay quietly do their work.
- Volatility spillover: concentrated 0DTE gamma can amplify intraday swings that hit long-term investors who never played.
- Cultural drift: when speculation is framed as savvy, the habit of patient ownership erodes.
Why bans are the wrong answer
Prohibition would be both futile and paternalistic; the demand is real and would migrate offshore or into worse venues. The better tools are friction and honesty. Require plain-language disclosure of expected outcomes over time, not just single-trade payouts. Impose suitability checks and position limits for accounts using leverage they cannot cover. Tax the churn if the externalities warrant it.
Call the thing by its name
The point of this column is not to scold anyone for wanting excitement. It is to insist we stop laundering gambling through the vocabulary of markets. When the same 22-year-old holds a 0DTE call, a Kalshi contract, and a sports parlay, the industry owes them the truth about which of those, if any, builds wealth.
The counterargument, that adults have every right to gamble, is true and beside the point. Nobody here proposes banning risk. The argument is that a market granting itself the prestige of finance while operating the economics of a casino owes its customers the same candor a casino is legally required to provide. A slot machine posts its odds. A $57 trillion same-day market that runs on gamma and decay should be held to no lower a standard.
A market that runs a $57 trillion same-day casino has an obligation to label the door. Right now it is selling admission and calling it an education.