Guide to 0DTE Trading: 5 Strategies Powered by Real-Time Dealer Data

A 30DTE option and a 0DTE option share the same ticker but live in completely different universes. With hours — not weeks — until expiration, the Greeks behave differently: Gamma is extreme. ATM gamma scales as 1/√T — when T is measured in hours, not days, gamma is 3–10× higher than weekly options. Theta decay is non-linear. 0DTE theta bleeds slowly in the morning, doubles by 2 PM, and can hit 5× the morning rate by 3:30 PM. Dealers hedge aggressively. Because gamma is so high, every $1 move in the underlying forces dealers to buy or sell significantly more shares than equivalent moves in longer-dated contracts. Pin risk is real. With massive OI concentrated in a few strikes, price can be magnetically attracted to high-OI levels as expiration approaches. This isn't theory — it creates real order flow. When dealers are short 50,000 SPY contracts at the 590 strike and SPY drops $1, they must sell hundreds of thousands of shares to stay hedged. That selling is not discretionary. It's mech