Gamma Exposure (GEX) measures how much market makers must buy or sell the underlying when the price moves by $1. It is computed from options chain data (open interest and implied volatility) using Black-Scholes gamma across the nearest 6 expirations. Positive GEX (green) = dealers buy dips and sell rallies, stabilizing price. Negative GEX (red) = dealers sell dips and buy rallies, amplifying moves. The Call Wall is the strike with largest positive gamma (resistance). The Put Wall is the strike with largest negative gamma (support). Data covers S&P 500 + Nasdaq 100 (~520 stocks). End-of-day only (OI updates once daily).
When you click a stock, the detail view shows 11 summary cards. Here is what each one means:
Net GEX — Total gamma exposure across all strikes. Positive = market makers stabilize price (buy dips, sell rallies). Negative = they amplify moves. Think of it as a "market shock absorber" gauge.
Regime — Positive = calm, mean-reverting market. Negative = volatile, trend-following. Most stocks are positive most of the time.
Call GEX / Put GEX — Gamma from call vs put options separately. The OI number below is how many option contracts are open (each = 100 shares).
P/C Ratio — Put/Call Open Interest ratio. Below 0.7 = bullish (more calls than puts). Above 1.0 = bearish (more puts = more hedging/fear). Around 0.7-1.0 = neutral.
Avg IV — Average Implied Volatility. This is the market's forecast of how much the stock will move. 20-30% = low/calm. 30-50% = moderate. 50%+ = high/volatile (earnings, news). Higher IV = more expensive options.
Net Delta — If the stock moves $1 up, market makers' total position changes by this many "share equivalents." Positive = net long bias (bullish pressure). The number is large because it's summed across all contracts × 100 shares each. Example: 45.5M shares means ~$8.6B of directional exposure for a $188 stock.
Total Vega — If implied volatility increases by 1%, the total value of all options changes by this dollar amount. Large vega = the stock is very sensitive to volatility changes (e.g. before earnings).
Total Theta — How much value all options lose per day to time decay. Always negative (options lose value over time). Large theta near expiration = lots of time premium eroding daily. This is money flowing from option buyers to sellers every day.
The Greeks Profile table shows the 10 strikes closest to the current stock price. The ATM (At The Money) row is highlighted in blue — this is where the stock price is right now, and where options are most active.
Why are the numbers so large? Each number is the Greek value × open interest × 100 (shares per contract), summed across all expirations. So "Call Δ = 3.4M" at the $187.50 strike means: if NVDA goes up $1, market makers holding calls at this strike gain the equivalent of 3.4 million shares of exposure.
Call Δ (Delta) — Directional exposure from call options at this strike. Positive = bullish. Larger at ITM (below spot) strikes, smaller at OTM (above spot).
Put Δ (Delta) — Directional exposure from put options. Always negative = bearish. Larger at ITM puts (above spot).
Net Δ — Call + Put delta combined. Green/positive = bullish pressure, Red/negative = bearish pressure. Strikes with large Net Delta act as magnets — price tends to gravitate toward them.
Vega $ — Volatility sensitivity. High vega strikes are where option value changes most when IV shifts. Peaks at ATM. If you expect a volatility event (earnings, Fed), watch the high-vega strikes.
Call Θ / Put Θ / Net Θ — Daily time decay in dollars. Always negative. Largest at ATM and near-expiry options. This is the "rent" option holders pay every day. Strikes with large negative theta = lots of premium eroding, which drives selling pressure as expiry approaches.
Practical use: Look for strikes where Net Delta is extremely large — these act as support/resistance because market makers must hedge aggressively there. High Vega strikes are sensitive to news. High Theta strikes have time pressure that accelerates into expiration week.
What: Put volume divided by call volume today. Higher = more bearish bets.
Normal: 0.7–1.0 for SPY (stocks vary). Above 1.0 means more puts than calls being bought.
Extremes: Below 0.5 = euphoria (top warning, contrarian). Above 1.3 = panic (bottom signal, contrarian).
Use it: Spikes into extreme zones often mark reversals. Don't trade it as a directional indicator — it's a sentiment gauge. The crowd is usually wrong at the extremes.
What: How many open contracts exist at each strike (call OI in green, put OI in red). The blue line marks current spot.
Call walls: Big green bars above price act as resistance — dealers must sell into rallies to stay hedged.
Put walls: Big red bars below price act as support — dealers must buy into dips to stay hedged.
Max pain: The strike with the most combined OI. Price tends to gravitate there into expiry (Friday for weeklies).
Use it: Trade with the walls, not against them. Big walls are magnet levels.
What: Contracts where today's volume is more than 2x the open interest — meaning someone is making a big new bet (the activity isn't from existing positions being closed).
Vol/OI: 2–5x = unusual. 5–10x = highly unusual. 10x+ = block trade or institutional flow.
Type: Unusual CALL = bullish bet (or short hedge). Unusual PUT = bearish bet (or long hedge).
Strike: Near-the-money = directional bet on the stock. Far OTM = lottery ticket or hedge. Deep ITM = stock proxy.
Expiry: Short-dated = directional speculation on a near-term move. Long-dated = strategic positioning.
Use it: Look for institutional fingerprints — large blocks at liquid ATM strikes. Retail tends to buy small lots of OTM lottery tickets, which is noise.
IV: Implied Volatility — the market's expected future stock volatility. Higher IV = options are more expensive (priced as if the stock will move a lot).
IV Rank: 0–100 score showing where current IV sits in its 1-year range. >80 = expensive (good time to SELL premium). <20 = cheap (good time to BUY premium). 50 = neutral.
IV Percentile: % of past days when IV was lower than today. 80% means you're in the top 20% of IV days for the year — comparable to IV Rank but more sensitive to outliers.
Strategy hint: High IV (Rank > 80) = sell credit spreads, iron condors, covered calls, cash-secured puts. Low IV (Rank < 20) = buy long calls/puts, debit spreads, calendars.
Don't confuse: IV says how much the market expects movement, not which way. High IV alone doesn't mean bearish — it means uncertain.
What: Implied volatility of S&P 500 options — the "fear gauge". Reflects expected market volatility for the next 30 days.
Zones: <15 = complacency. 15–20 = calm/normal. 20–25 = elevated concern. 25–30 = significant fear. >30 = panic/crisis.
Mean-reverting: VIX spikes are usually short-lived. Sustained high VIX (weeks) is unusual and bearish for stocks.
Contrarian use: When VIX spikes above 30 and the market is selling off, that often marks a tradable bottom. When VIX is below 15 for weeks, complacency is high and downside risk grows.
What: 30-day history of average ATM implied volatility for this ticker.
Rising IV: Market is pricing in more uncertainty (could be earnings approaching, news event, sentiment shift). Options getting more expensive.
Falling IV: Uncertainty resolving, options getting cheaper. Often happens after earnings ("IV crush") or after a feared event passes without incident.
Compare to VIX: If this stock's IV is rising while VIX is flat, the move is stock-specific (idiosyncratic). If both are rising, it's market-wide.