People make it sound so complicated and mysterious. But honestly, the reason isn’t that complex. Market makers don’t manipulate the market—they just earn the bid-ask spread plus fees. Before the CPI release, the market was super bullish, and calls were overcrowded. At the same time, 0DTE volatility was suppressed to very low levels. Once the downside volatility expanded, call buyers had to close their positions, and the puts sold by market makers caused a sharp increase in gamma pressure (since the implied movement before CPI was only 33bp). So, in the futures market, they could only keep selling as prices dropped, pushing it all the way down. That’s it.