- 0DTE
- "Zero days to expiration" — an option expiring the same day it's traded. Maximum gamma and time decay; the fastest-moving options on the board. See our 0DTE Guide.
- Assignment
- When the seller of an option is obligated to fulfill it — delivering or buying shares at the strike. Long option buyers exercise; short sellers get assigned.
- At-the-money (ATM)
- An option whose strike is at (or nearest) the current underlying price. ATM options have the highest gamma and time value.
- Breakeven
- The underlying price at which a trade neither makes nor loses money at expiration. For a long call it's strike + premium; for a long put, strike − premium. Try the profit calculator.
- Call option
- The right to BUY the underlying at the strike price before expiration. Gains value as the underlying rises.
- Call wall
- The strike with the heaviest positive dealer gamma above spot — where upside tends to stall. Part of the dealer-positioning map.
- Delta
- How much an option's price moves per $1 move in the underlying; also a rough probability of finishing in the money. Compute it in the Greeks calculator.
- Expected move
- The ±1-standard-deviation range the options market is pricing over a period, from implied volatility. See the expected-move calculator.
- Extrinsic value
- The part of an option's premium that is NOT intrinsic value — time value plus volatility value. It decays to zero at expiration.
- Gamma
- How fast delta changes as the underlying moves. Highest at-the-money and near expiration — the engine behind 0DTE's violence.
- Gamma exposure (GEX)
- An estimate of how much dealers must hedge as price moves. Positive net GEX dampens moves (pinning); negative amplifies them. See GEX tools.
- Gamma flip
- The price level where net dealer gamma crosses zero — the line between the damping (positive) and amplifying (negative) regimes.
- Implied volatility (IV)
- The market's forward estimate of how volatile the underlying will be, backed out of option prices. Higher IV = richer premiums and a wider expected move.
- In-the-money (ITM)
- An option with intrinsic value — a call whose strike is below spot, or a put whose strike is above it.
- Intrinsic value
- The in-the-money amount of an option: max(0, spot − strike) for a call, max(0, strike − spot) for a put.
- Max pain
- The strike where the most option value expires worthless — a rough gravity level into expiration. Compute it in the max-pain calculator.
- Open interest (OI)
- The number of option contracts outstanding at a strike. Heavy OI concentrates dealer hedging and defines the walls.
- Out-of-the-money (OTM)
- An option with no intrinsic value — all premium is extrinsic (time + vol). Cheaper, lower delta, higher risk of expiring worthless.
- Premium
- The price paid (or received) for an option, quoted per share; one contract = 100 shares, so a $1.20 premium costs $120.
- Put option
- The right to SELL the underlying at the strike price. Gains value as the underlying falls.
- Put wall
- The strike with the heaviest dealer gamma below spot — where downside tends to find support.
- Rho
- An option's sensitivity to interest-rate changes. Small and rarely decisive for short-dated options.
- Straddle
- Buying a call and a put at the same strike — a bet on a big move in either direction. The ATM straddle price is the market's own expected-move estimate.
- Strike price
- The fixed price at which an option can be exercised. The reference point for intrinsic value and the dealer walls.
- Sweep
- An aggressive order split across multiple exchanges to fill fast — often a sign of urgent, informed flow.
- Theta
- The dollars of time value an option loses per day — "time decay." Brutal on 0DTE, where it drains the whole premium in hours.
- Vega
- How much an option's price changes per 1-point change in implied volatility. Long options are long vega.
- VIX / VXN / RVX
- The 30-day implied-volatility indexes for the S&P 500 (VIX), Nasdaq-100 (VXN) and Russell 2000 (RVX) — the market's "fear gauges." Live on our market-data page.
- Volatility skew
- The pattern of implied volatility across strikes — usually puts carry higher IV than calls (downside hedging demand).
- VWAP
- Volume-weighted average price — the average price weighted by volume over the session. A key intraday reference for scalpers.