Traders are piling into zero-days-to-expiration options, or 0DTE options. They are a cheap, fast but risky way to bet on the market that offers the chance of explosive returns if those bets are correct. These big wins can also lead to big losses as they are extremely risky investments. Retail traders have played a big role in driving 0DTE trading volumes to record highs. WSJ explains the rise and effect of 0DTE options on the stock market.