Zero-day-to-expiration options are contracts that expire the same day that they’re traded. The trading volume of 0DTE options tied to the S&P 500 surged to 8.5 million in April, a 23% jump since the beginning of the year and accounting for roughly 7% of the total volume in U.S. option markets, according to data from JPMorgan.

These securities have become a popular tool for investors, big and small, to make a quick buck or hedge against sudden event-driven moves in the broader market. Many argued that large volumes of these short-lived vehicles can exacerbate price swings in the market as dealers and market makers buy and sell underlying assets to balance their positions.