0DTE Options and Gamma: What Day Traders Need to Know

Zero-days-to-expiration options — contracts that expire the same day they're traded — have exploded in popularity. SPX now offers daily expirations (Monday through Friday), and 0DTE volume regularly accounts for 40-50% of total SPX options activity.

This matters for market structure because 0DTE options have uniquely extreme characteristics. At-the-money 0DTE options have the highest gamma of any contracts available. This means the hedging flows they generate are disproportionately large relative to their premium. A $2 SPX 0DTE call bought for $1.50 can force a market maker to buy 50+ SPX futures to hedge — and as price moves, that hedge adjusts rapidly.

The result: 0DTE options have become one of the largest drivers of intraday price action. Understanding their gamma characteristics isn't optional for day traders — it's essential.

0DTE options have extreme gamma characteristics:

Gamma is highly concentrated near the current price. A 0DTE option that's 5 points out of the money has almost no gamma. An at-the-money 0DTE option has the highest gamma of any listed contract. This creates a sharp "spike" in the gamma profile around the current price.

Gamma decays throughout the day. At 9:30 AM, a 0DTE option has 6.5 hours of time value. By 3:30 PM, it has 30 minutes. The gamma of at-the-money options actually increases as expiration approaches (in absolute terms), but the total gamma exposure decreases as contracts are closed or move away from the money.

The hedging impact is front-loaded. Most 0DTE volume is concentrated in the first two hours. As the day progresses, positions are closed and new openings slow. The highest structural impact of 0DTE gamma is typically from 9:30 AM to 11:30 AM.

Use the intraday gamma spike as a magnet. Heavy 0DTE open interest at a specific strike creates a pinning effect — price tends to gravitate toward it, especially in the first few hours. If 0DTE activity is concentrated at 5700 on SPX, expect that level to act as a magnet.

Watch for 0DTE gamma flips. When large 0DTE call positions are opened, it adds positive gamma. When large put positions are opened, it adds negative gamma. Rapid shifts in 0DTE positioning can flip the intraday regime, even if the weekly/monthly gamma is unchanged.

Trade the "gamma melt" in the afternoon. As 0DTE contracts approach expiration, their gamma spikes for at-the-money strikes. If there's a large concentration of 0DTE open interest at a nearby strike, the final 90 minutes can produce sharp moves as dealers unwind hedges.

Combine 0DTE data with longer-dated structure. The best trades happen when 0DTE gamma and weekly/monthly gamma align at the same level. If the weekly Call Wall sits at the same price as a large 0DTE call concentration, that level has exceptional structural strength.

0DTE options have created a more dynamic intraday environment, but they haven't eliminated longer-term structure. The Call Wall, Put Wall, and Zero Gamma levels from weekly and monthly options still define the broader regime. 0DTE gamma creates noise within that structure.

Don't over-trade based on 0DTE shifts. The intraday gamma landscape changes rapidly, and chasing every shift leads to overtrading. Use 0DTE data to confirm or refute signals from the broader structural framework, not as a standalone trigger.

Remember that 0DTE data is noisier. Positions open and close within minutes. The 15-minute MarketOptix refresh captures the trend but may not catch every spike. Focus on large, persistent 0DTE concentrations rather than small, transient ones.

The most important thing: know whether the broader gamma regime is positive or negative before trading 0DTE setups. A 0DTE call concentration means one thing in positive gamma (strong pin) and another in negative gamma (potential squeeze).