Option walls are the strikes that hold the largest open interest in a series. The Call Wall is the strike with the most open calls, the Put Wall the strike with the most open puts. On the chart they appear as horizontal levels above and below price.
Why price often reacts at walls
An option is a contract with two sides. Whoever sold a large block of calls at a strike starts losing money once price rises above that strike plus the premium received. That seller has a reason to defend the level: selling futures on the approach, restructuring, hedging. Puts work in mirror image: the seller is hurt by a drop below the strike.
The second reason is market-maker hedging. The more contracts sit at a strike and the closer expiration is, the more actively hedges are adjusted as price approaches. Hence the familiar "pinning" to large strikes in the last days of a series.
One caveat matters: the exchange report shows how many contracts are open, not who is the buyer and who is the seller. A wall is a place where large participants have an interest, not a guaranteed reversal.
How walls look in OLIMP
- Call Wall: red lines above price, acting as resistance. Put Wall: green lines below price, acting as support.
- The main wall is a thick solid line; the next ones by size are dashed. The number of walls per side is set from 1 to 5 under "Contract" → "Balance".
- The label shows the strike and open interest. Hover for the remaining values.
- On inverse pairs (USDJPY, USDCHF, USDCAD) the indicator converts prices and swaps the roles of the walls automatically.
Market range: walls adjusted for premium
An option seller starts losing not at the strike itself but further out, by the amount of premium received. That point is the breakeven. The "market range (walls)" option shades the corridor from the breakeven of the main put wall to the breakeven of the main call wall. Inside it, the sellers of both walls remain in profit.
With "Contract history" on, the corridor is drawn for every report, so you can see whether it narrows, widens or shifts after price.
Telling a live wall from a fading one
A wall's size is accumulated history. What is happening to it now matters more.
- Inflow at the wall: open interest is growing, a participant is adding. The level is getting stronger.
- Outflow at the wall: positions are being closed. Yesterday's wall may be empty before price gets there.
- The wall moves: in contract history the main wall shifts to another strike. A direct sign that positions are being rolled.
Tracking growth and decay of positions is covered in OI flows: progress and regress.
Walls and market regime
The same wall behaves differently depending on where price is relative to the Gamma-Flip level ("Volat." sub-tab). Above it, market makers hedge against the move and approaches to walls are more often absorbed. Below it, hedging goes with the move and a break of a wall can accelerate. So read a wall together with the regime, not in isolation.
Open-interest profile
For the full picture rather than only the largest strikes, turn on "OI profile": a horizontal histogram across all strikes at the right edge of the chart. Peaks are walls; gaps are zones with few positions. Modes: both types, calls only or puts only.
Example: gold, early October 2026
From September 25 to October 2, gold futures fell from $4,330 to $4,165. In the series expiring October 27, 3,064 calls were added at the $4,510 strike and 1,369 at $4,400, both above price. In puts the largest inflow was at $3,800: 2,495 contracts, roughly 9% below the market. Puts at $4,400, now deep in the money after the decline, were cut by 1,019 contracts.
How to read it. Positions were built at two strikes above, and $4,400 also coincides with the Max Pain of the expired September series. Below, the large put strikes are $4,000 and $3,800, and the lower edge of the ±1σ corridor (about $4,006) runs next to the first. The result is a corridor where the origin of each boundary is clear. Whether buyers or sellers sit at those strikes the report does not say, so this is a map of interest, not a direction.
Questions and answers
How many walls should I show? One or two per side is enough to start. Three or more are useful when price has already reached the main wall and you need to see what lies beyond.
Is the call wall always above price? Usually, but after a strong rally price can end up above the strike with the most calls. Those calls are then in the money and the level acts as support from below.
How is a wall different from a chart support level? A chart level is drawn from past price reversals. A wall comes from currently open positions: it is not history but what is in the market now, and it disappears on expiration day.
What happens to walls after expiration? The series' positions are gone and its walls lose their force (more in CME options expiration: what it is and how it affects price). Look at the next series with the right arrow in the "Contract" row.
Common mistakes
- Assuming a wall cannot break. Walls do break, especially once positions leave them.
- Watching only the monthly series. On the expiration day of a weekly series its walls can matter more than the monthly ones.
- Forgetting the price offset. Levels are in CME futures prices. If your broker quotes spot or a CFD, turn on alignment on the "FP" tab or the wall will appear shifted.
- Not checking the date. The report comes out once a day. On CME holidays levels do not update; the report date is in the info panel.
Current walls for each instrument, without installing the indicator, are in Analytics. To see them on your own chart, download the indicator: walls are available without a key as well.
This article describes open positions based on exchange data and is not investment advice.