What are 0DTE Options?
0DTE — zero days to expiration — are options contracts that expire the same trading day they're held. On SPY, 0DTE contracts now account for a huge share of daily options volume, and their extreme gamma profile makes dealer hedging the single biggest force driving intraday price action.
A 0DTE option is any listed option whose expiration date is today. At the moment of trading, the contract has hours — sometimes minutes — of life left before it either settles in-the-money or expires worthless.
The term became mainstream in 2022 when daily-expiration options on major index ETFs became the norm. Before that, SPY only had Monday/Wednesday/Friday weekly expirations. Now SPY has daily expirations Monday through Friday, which means every trading day is someone's 0DTE.
0DTE is a rolling label, not a product type. A contract sold on Wednesday expiring Friday becomes 0DTE on Friday morning. The mechanics and the options chain are identical to any other listed option — only the time-to-expiry differs.
Short-dated options concentrate an option's Greeks at extreme levels. Two effects dominate:
Theta collapse. Time decay accelerates non-linearly into expiration. A 0DTE option can lose 50% of its value in an hour if the underlying doesn't move in its favor. For buyers this is brutal; for sellers it's the attraction.
Gamma explosion near the strike. As an option approaches expiration, its gamma near at-the-money spikes. Small moves in the underlying produce very large changes in delta. This is the single most important fact about 0DTE from a dealer-hedging perspective — a 0DTE option pinned at-the-money has dramatically more gamma per contract than a 30-DTE option at the same strike.
The structural consequence: because gamma is so concentrated near at-the-money 0DTE strikes, dealer hedging flows on those strikes dominate the order book through the day — and especially into the final hour before settlement.
Every 0DTE option that retail buys has to be sold by someone — typically a market maker. Because MMs hedge to stay directionally neutral, each contract they sell forces them into an offsetting position in the underlying.
When price moves toward a heavily-traded 0DTE strike, dealer gamma near that strike spikes, and the hedging required to stay neutral becomes very large relative to the cash needed to move the underlying. Two patterns result:
- Pinning into the close. Large open interest at a strike pulls price toward that strike via hedging feedback. See options pinning.
- Squeeze-style breakouts. When a heavy 0DTE call strike is breached to the upside in a negative-gamma environment, dealer short-gamma hedging amplifies the move — the intraday version of a gamma squeeze.
This is why "reading the tape" on SPY now means reading the gamma profile. The order book looks random until you overlay dealer gamma.
SPY opens at 500. The 0DTE options chain shows massive open interest at the 501 call — roughly 80,000 contracts — with dealers assumed short that gamma.
Through the morning, SPY grinds up toward 501. Every step closer, the 501 call's gamma spikes. Dealers who sold the call need to buy more SPY to stay hedged — their buying pushes price up, which forces them to buy more, and so on.
SPY tags 501, dealer short-gamma hedging peaks, and the move stalls. Price oscillates tightly around 501 for the rest of the session as the strike's gravitational pull from hedging flows dominates any directional flow.
After settlement, the gamma vanishes. Tomorrow is a different chain, a different profile, a different regime.
0DTE options carry extreme risk. Rapid time decay means a contract can expire worthless within hours. Leverage amplifies losses as well as gains. 0DTE is not suitable for all traders — only engage with capital you can afford to lose.
0DTE rewards preparation and punishes guesswork. Price behavior is governed by the options chain itself — gamma walls, regime state, dealer positioning — not by the kinds of signals that work on longer timeframes. A trader who walks in without a read on the current structure is effectively trading blind on the shortest-timeframe, highest-leverage product listed.