This tool estimates options-based support/resistance structure for SPX, SPY and QQQ from the free CBOE delayed options chain. Everything is recalculated from a fresh snapshot every 30 seconds. It is an educational market-structure tool — not financial advice.
Gamma exposure (GEX) estimates how much option dealers must hedge as the underlying moves. Per contract:
GEX = gamma × open interest × 100 × spot² × 0.01
Calls count positive, puts negative (the standard dealer-positioning convention: dealers are assumed long calls / short puts). The result is dollars of hedging flow per 1% move in the underlying.
Rows are strikes (high → low), columns are the next 14 expirations, cell color is net GEX at that strike × expiration. The white dashed line marks spot. Scan around spot: big green above = potential resistance/pin, big green below = potential support; red clusters = unstable zones. The same-day column usually dominates intraday behavior.
The tornado chart shows call GEX (green, right) and put GEX (red, left) per strike for the selected expiration, with the net profile overlaid. Lines mark:
Same-day expiration only, with a tighter ±3% strike window: 0DTE share of total volume, 0DTE net GEX, and the day's own walls/flip. SPX lists daily expirations; on non-trading days this tab shows the next expiry.
Call and put volume (or traded premium) by strike for the selected expiration, plus the largest contracts by premium. Side (buy/sell) is a heuristic — last trade at/above the ask counts as buying, at/below the bid as selling. A big flow number is not automatically bullish or bearish; combine it with the heatmap and strike map.
A weighted composite of eight indicators, each scored −100…+100:
| Component | Weight | Bullish when… |
|---|---|---|
| Gamma regime (spot vs flip) | 20% | spot well above the flip |
| Put/Call ratio (volume) | 15% | calls outpace puts |
| Delta-exposure tilt | 15% | net delta exposure positive |
| VIX day change | 15% | VIX falling |
| Put/Call ratio (OI) | 10% | below the ~1.2 index baseline |
| 25Δ IV skew (~30 DTE) | 10% | put skew below ~4 vol pts |
| Price momentum (day) | 10% | underlying up on the day |
| IV30 day change | 5% | implied vol falling |
Missing components (e.g. VIX feed down) are dropped and weights renormalized. Labels: ≥+50 Strongly Bullish, +15…+50 Bullish, ±15 Neutral, −15…−50 Bearish, ≤−50 Strongly Bearish.
SPX, SPY and QQQ side by side. Walls and flip are shown in % distance from spot so the three markets are directly comparable. Agreement across all three (same regime) makes the structure more reliable; divergence is a caution flag.