Put Wall
Canonical definition, formula, interpretation rules, and live API reference for the put wall level.
The strike with the highest concentration of put-side gamma exposure (absolute value) — acts as downside support in positive gamma regimes because dealers buy here on dips to re-hedge their short gamma at that strike.
Where put_GEXᵢ is the put-side gamma exposure at strike i, computed as Γᵢ × OIᵢ × 100 × S for put contracts only (negative value). The strike with the highest absolute value is the put wall.
- Support in positive gamma: price tends to bounce off the put wall as dealer buying absorbs selling pressure.
- Breakdown signal: a break below the put wall usually accelerates the decline as dealer support collapses.
- Weakens in negative gamma: when the regime is negative gamma, the put wall's support effect is reduced as dealer hedging dynamics shift.
Live Example: SPY
Live SPY put wall data temporarily unavailable. See /stock/spy/gamma for current values.
Get Put Wall via API
symbol(path, required) — underlying ticker, e.g.SPY
{
"symbol": "SPY",
"underlying_price": number,
"gamma_flip": number,
"call_wall": number,
"call_wall_gex": number,
"put_wall": number,
"put_wall_gex": number,
"net_gex": number,
"net_gex_label": "positive" | "negative"
}curl -H "X-Api-Key: YOUR_KEY" \
https://lab.flashalpha.com/v1/exposure/levels/SPYWhy Put Wall Matters for Trading
The put wall is the strike with the largest negative dealer gamma — downside support in positive gamma, a waterfall trigger in negative gamma.
- What it measures
- The strike with the largest put-side dealer gamma concentration. Typically below spot.
- What it signals
- Where dealer hedging creates the strongest bid on dips. Price often holds the wall in positive-gamma regimes.
- Why we measure it
- Options-derived support is data-driven and updates in real time — more reliable than trendline support once you know how to read it.
- Who uses it
- Day traders, index ETF traders, systematic flow traders, 0DTE scalpers.
How to read Put Wall
- Strong support on approach
- Dealers buy into weakness near wall
- Long-at-wall setups work
- Often pins near wall on OPEX
- Break of wall accelerates downside
- Dealers short-gamma sell into the break
- Waterfall until next concentrated strike
- Classic crash mechanics
- Concentration too small to matter
- Use next-strongest strike
- Weak reference only
- Common in illiquid names
Rules of thumb
- Regime sets the behaviour. Same wall: support in positive gamma, waterfall trigger in negative. Check regime.
- Pair with call wall. Together they define the expected intraday range when in positive gamma.
- Watch the break, not the touch. A touch without closure is noise. A close-through on volume is regime-shifting.
- 0DTE put walls dominate close. Same-day expiry concentration outweighs the full-chain wall in the final hour.
- Strength = % of total GEX. Weight the wall by fraction of chain gamma, not raw number.
How to Read the Put Wall
The put wall is your primary downside support level derived from the options market. Start by checking the distance between spot and the put wall. When price is approaching the put wall from above in a positive gamma regime, expect dealers to buy aggressively to re-hedge their short put positions. This creates a floor where sell-offs tend to find support.
The strength of the put wall depends on two factors: the gamma concentration at that strike (higher absolute value = stronger support) and the current regime. In positive gamma, the put wall is reliable support. In negative gamma, dealer hedging dynamics shift and the put wall's support weakens — breakdowns accelerate more easily.
Combine the put wall with the call wall to define the expected dealer range. In a typical positive gamma session, price oscillates between the put wall (support) and call wall (resistance). A break below the put wall is one of the most important intraday signals — it often triggers a cascade as dealer support disappears, frequently coinciding with a transition into negative gamma where hedging flows amplify the decline.
Related Concepts
The strike with the highest call gamma concentration — the upside counterpart to the put wall, acting as resistance.
The price level where net GEX crosses zero — the boundary between positive and negative gamma regimes.
Net dealer gamma exposure — the force that creates the put wall, call wall, and gamma flip levels.
The strike where total option holder loss is minimized at expiration — related to the put wall through dealer positioning.
Learn More
Complete guide to options-derived levels with dealer mechanics and trading applications.
Full endpoint reference with parameters, response schema, and tier limits.
Put wall, call wall, and gamma flip visualisation for any US equity or ETF.
The upside resistance counterpart to the put wall — together they frame the dealer range.
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