Open Interest Heatmap Tool
The Realtime Options Open Interest Heatmap is an interactive strike-by-expiry grid for inspecting where one symbol's outstanding contracts are concentrated. Strikes run up the vertical axis with price, expiries run across with the nearest on the left, green is call-side and red is put-side. Filters, concentration metrics and churn separate active areas from legacy positioning, while call wall and put wall labels remain reference points rather than forecasts.
- Research question
- Which strikes carry the outstanding positions, and how far is spot from them?
- Best used for
- Finding the levels worth watching before an expiry
- Data timing
- Near-real-time Pro; 15-minute delayed trial
- Product access
- Included in the single $29/month plan
What the open interest heatmap tool shows
Read concentration, not certainty. Top-five share tells you how concentrated a symbol's whole chain is around its heaviest strikes; a high number means the call wall and put wall are meaningful references, a low one means they barely stand out from the rest of the chain. Concentration is a tendency and not a rule: a large enough directional move runs straight through even a heavy strike, and the heatmap gives no advance warning when that is about to happen.
Read the supporting context
The screenshot above is from the working product, not a mockup. The visible controls and fields are the same ones trial and Pro users research with; only the market-data timing changes between the two access levels.
- One cell per strike and expiry, coloured green for call-side and red for put-side. Opacity carries size and saturation carries how lopsided the strike is, so a balanced strike stays grey.
- Call wall, put wall, pin zone width, OI centre, put/call OI ratio and the share of total open interest held by the top five strikes.
- Four metrics on the same grid: total OI, call OI minus put OI, churn (session size traded divided by open interest) and bias (net directional premium share inferred from bid/ask evidence).
- An expiry filter for 0DTE, seven days, thirty days or the full chain, plus a slider for how many strikes to keep around spot.
- A horizontal put and call OI profile down the right edge, and per-expiry totals along the bottom.
How to read this dashboard
Read the dashboard as one step in a sequence. Record what it directly shows first, then use the next view to test the interpretation rather than turning a color or ranking into a conclusion.
- Read the KPI row first. Spot, call wall and put wall give the frame; the percentages beside each wall are its distance from spot.
- Check the pin zone width. A narrow band means the two walls are close together and spot has little room between them; a wide one means the map is not saying much about near-term levels.
- Look at top-5 share before trusting any single strike. If five strikes hold 41% of the chain, positioning is concentrated. If they hold 12%, it is spread out and the walls are weaker references.
- Switch the metric to Churn to separate levels the tape is working today from strikes that only carry legacy positions.
- Narrow the expiry filter to 0DTE or seven days. Walls that only exist in a September expiry rarely matter to a Tuesday session.
What this view cannot establish
Open interest is the latest clearing snapshot for each contract and it updates overnight, so nothing on this grid can tell you whether today's activity opened or closed a position. Every open contract has a long and a short side, which means a wall is not a directional vote. The colour scale also caps at the 95th percentile of visible cells so one crowded strike cannot flatten the rest, and that makes the top of the range look flatter than the raw numbers are.
Read the supporting context
Realtime Options organises observed and derived market data for independent research. Read each view with its stated method, assumptions and surrounding context.
Common questions
What is an open interest heatmap?
It is a grid of strikes against expiries where colour shows how much open interest sits in each contract. It turns an option chain that would take several screens of numbers into one picture of where positions are concentrated.
What does the top-five share number mean?
It is the percentage of a symbol's total open interest held by its five heaviest strikes. A high top-five share means positioning is concentrated and the call wall and put wall carry more weight; a low one means positioning is spread out and the top strike is barely different from the tenth. For how the call wall and put wall are calculated and why they sometimes slow price, see the dedicated call wall and put wall guide.
What does the pin zone tell me?
The pin zone is the distance between the put wall and the call wall, shown as a percentage of spot. A narrow zone means the heaviest positioning sits close on both sides of the current price, which is the setup people mean by pinning into expiry.
Is the open interest heatmap updated in real time?
No, and no provider can offer that. Open interest is published by OCC after the clearing process runs, so an intraday heatmap shows the previous session's cleared figures. The churn metric is the intraday layer, because it divides today's traded size by that snapshot.
Does this show max pain?
No. Max pain is a separate calculation that finds the strike where the largest total value of options would expire worthless. The heatmap shows where open interest actually sits, which is the input to that calculation rather than the result of it.