How to Read SPX 0DTE Customer Position by Strike

The one-minute explanation

On the SPX 0DTE page, Customer Breakdown by Strike groups today’s option activity by strike price. Instead of reading thousands of individual trades, you can see which strikes have more buy-side or sell-side pressure in calls and puts.

Think of each strike as a shelf in a store. The chart shows whether more call or put contracts have been added to one side of that shelf during the session. It helps you find the areas worth watching when SPX gets close to them.

Start here: this is context, not a forecast. A large bar says that the day’s classified activity is concentrated at that strike. It does not say price must stop, reverse, or travel there.

What you are looking at

RowsEach horizontal row is an SPX strike. Higher strikes appear higher on the chart; lower strikes appear below.

GreenCalls. Green always identifies the call side, whether its bar is left or right of zero.

RedPuts. Red always identifies the put side, whether its bar is left or right of zero.

Middle lineThe zero line. Bars to the right are positive for the selected view; bars to the left are negative.

DotsComparison points show the prior selected window and the opening snapshot, so you can see whether a level is building, shrinking, or staying steady.

Spot lineThe highlighted horizontal guide marks the current SPX area. Begin with the strikes closest to it.

How to read the Position view

In the default Position view, the chart estimates the net direction of today’s classified customer flow at each strike. The word “net” matters: buy activity is offset by sell activity. A bar can shrink later in the day when the opposite side trades.

What the bar showsWhere it appearsPlain-English read

What the bar showsCalls Net long

Where it appearsRight of zero

Plain-English readMore classified call buying than selling. That is upside-oriented activity.

What the bar showsCalls Net short

Where it appearsLeft of zero

Plain-English readMore classified call selling than buying. That is downside or capped-upside activity.

What the bar showsPuts Net long

Where it appearsRight of zero

Plain-English readMore classified put buying than selling. That is downside-oriented activity or protection.

What the bar showsPuts Net short

Where it appearsLeft of zero

Plain-English readMore classified put selling than buying. That is upside-oriented activity or premium-selling activity.

Here is the easy rule: green on the right and red on the left can both lean bullish; green on the left and red on the right can both lean bearish. The color tells you the option type. The side of the center line tells you the sign.

A simple way to use the live chart

Find spot first. Locate the highlighted SPX price area and note the two or three nearby strikes.
Look for concentration. Longer bars mean more net classified activity at that strike relative to the other displayed strikes.
Check the dots. If the current bar has grown away from its earlier dot, that pressure has increased in the chosen window. If it has moved back toward zero, it has faded.
Change the time window. Use 5M, 15M, or 30M to compare the current reading with a recent snapshot. Short windows show quick changes; longer windows show more of the session’s structure.
Watch price behavior. The chart identifies a level of interest; price action and risk management decide whether there is a trade.

Why 0DTE makes the chart useful—and fast-moving

0DTE means “zero days to expiration”: these SPX options expire the same day. Activity can concentrate around nearby strikes and can change quickly as traders open, close, hedge, or roll positions. That is why the chart is most useful as an intraday map, not as a static prediction for the whole day.

For example, a large call bar near the current price tells you that strike is active. If SPX approaches it, check whether the bar is still growing, whether put activity is appearing nearby, and whether price is accepting or rejecting that area. The best question is not “what will happen?” but “what is changing as price reaches this strike?”

The other two tabs: DEX and MM GEX

The same strike map has two additional lenses. They use the same calls-green, puts-red color language, but they answer different questions.

Customer DEXWeights the inferred customer flow by delta—how much an option tends to move when SPX moves. It helps show which strikes carry more directional sensitivity, not just more contracts.

MM GEXExpresses the model’s market-maker gamma view from the inferred customer-flow side. Positive and negative gamma can imply different hedging behavior, but it is a model-based exposure estimate, not a record of any market maker’s actual book.

If you are new to the page, start with Position. After you can read the call/put bars and their changes, use DEX and MM GEX as extra context rather than trying to make a decision from one number.

What this chart cannot know

Important limitation: “Customer Position” is a convenient name for the chart view. The values are inferred from classified intraday trades and a simplified counterparty model. They are not verified customer account holdings, and they do not identify who placed a trade.

A trade may be part of a spread, hedge, roll, or multi-leg strategy—not a simple directional bet.
Trade classification can be incomplete or uncertain, especially when quotes move quickly.
Open interest is a separate, prior-close background measure. It does not reveal who is long or short intraday.
Large activity at one strike can matter without becoming support, resistance, or a price target.

Use the chart to organize attention and manage risk. Pair it with price, liquidity, time of day, and a predefined stop—not with certainty.

Bottom line

Customer Breakdown by Strike gives you a cleaner question to ask during a fast 0DTE session: which nearby strikes are attracting meaningful call or put pressure, and is that pressure strengthening or fading? That is much more useful than trying to interpret the option tape one print at a time.