0DTE stands for zero days to expiration. These are options that expire at the end of today's session. A few years ago they were a niche product. Now they are a large share of S&P 500 options volume.

Why they matter to futures traders

0DTE options have very high gamma near the money. Small moves change their delta a lot, which means dealers have to hedge quickly and often. That hedging shows up in the futures market during the session.

What it does to the day

• Positioning can shift inside a single session, so morning levels are not the full story.

• Strikes with heavy 0DTE interest can act as intraday magnets, especially after lunch.

• Into the last hour, gamma near the money gets extreme. Moves can accelerate or freeze around big strikes.

How to adapt

• Recheck gamma levels after the first hour, not just before the open.

• Expect stronger pinning behaviour in quiet afternoons near large strikes.

• Be careful fading late moves on high volume. Hedging flow can be very one-sided into the close.

In HOC

The Option GEX Heatmap on HOC Charts shows how gamma at each strike changes through the day, which is the best way to see 0DTE positioning build in real time.

Next episode: vanna and charm, the two hidden flows that move the market even when price stands still.