Speed (∂³V/∂S³)

Third-order Greek measuring how gamma changes with the underlying price — the "gamma of gamma".

Definition

The third partial derivative of option value with respect to the underlying spot price. Speed quantifies how rapidly gamma changes as spot moves, making it essential for dynamic hedging of portfolios with concentrated gamma exposure.

Formula
Speed = ∂Γ/∂S = -(Γ / S) × [ (d₁ / (σ√t)) + 2 ]

Where Γ is gamma, d₁ is the standard Black-Scholes d₁ term, σ is implied volatility, t is time to expiry, and S is spot price. Speed is typically a very small number and is quoted per unit move in the underlying.

Inputs
spot price strike price time to expiry implied vol
API Field
third_order.speed
Interpretation
  • Positive speed: gamma is increasing as spot rises. The option is becoming more convex — delta will accelerate faster on further up-moves.
  • Negative speed: gamma is decreasing as spot rises. The option's convexity is flattening — delta acceleration is slowing.
  • Near ATM: speed is near zero at the money (gamma peaks there). Speed is most significant for OTM options approaching the strike.
  • Dynamic hedging: high absolute speed means gamma is unstable — re-hedging intervals must be tightened to avoid delta slippage.

Why Speed Matters

Gamma tells you how much delta will change for a unit move in spot. But gamma itself is not constant — it peaks at the money and falls off as the option moves into or out of the money. Speed measures this curvature of gamma. For a market maker hedging a large book, speed determines how quickly their gamma hedge becomes stale after a spot move.

Consider a portfolio that is long gamma near the current spot. As price moves away, gamma declines (speed is the rate of that decline). If speed is large, the hedge deteriorates rapidly, forcing more frequent and costly re-hedging. Conversely, if speed is low, the gamma profile is stable and hedges last longer.

Speed is particularly relevant around major option expirations when gamma is highly concentrated at a few strikes. A small spot move can shift the gamma profile dramatically, and speed is the metric that quantifies that instability.

Get Speed via API

Endpoint
GET /v1/pricing/greeks
Tier
Free
Parameters
  • spot (required) — underlying price
  • strike (required) — option strike price
  • dte (required) — days to expiration
  • sigma (required) — implied volatility (decimal)
  • type (required) — call or put
  • r (optional) — risk-free rate (default 0.05)
  • q (optional) — dividend yield (default 0.0)
Response field
{
  "third_order": {
    "speed": number,
    "zomma": number,
    "color": number,
    "ultima": number
  }
}
curl -H "X-Api-Key: YOUR_KEY" \
  "https://lab.flashalpha.com/v1/pricing/greeks?spot=550&strike=560&dte=30&sigma=0.18&type=call"
import requests
r = requests.get(
    "https://lab.flashalpha.com/v1/pricing/greeks",
    params={"spot": 550, "strike": 560, "dte": 30, "sigma": 0.18, "type": "call"},
    headers={"X-Api-Key": "YOUR_KEY"}
)
print(f"Speed: {r.json()['third_order']['speed']:.8f}")
const params = new URLSearchParams({
  spot: 550, strike: 560, dte: 30, sigma: 0.18, type: "call"
});
const r = await fetch(
  `https://lab.flashalpha.com/v1/pricing/greeks?${params}`,
  { headers: { "X-Api-Key": "YOUR_KEY" } }
);
const d = await r.json();
console.log(`Speed: ${d.third_order.speed}`);

Why Speed Matters for Trading

TL;DR

Speed is how fast gamma changes with spot. Positive speed = gamma grows into moves = accelerating convex profits. Negative speed = gamma shrinks = vanishing edge.

What it measures
∂Γ/∂S — third derivative of option value with respect to spot.
What it signals
The convexity of convexity. Whether your gamma position accelerates or decays.
Why we measure it
Big directional moves don't just change delta — they change gamma itself. Speed is the meta-convexity that matters in tail events.
Who uses it
Vol traders, tail-risk quants, gamma scalpers.

How to read Speed

Positive speed (long)
  • Gamma grows into the move
  • Accelerating convex gains
  • Sweet spot of long-option trades
  • Most valuable in tail events
Good for: long options, tail hedges
Negative speed (short)
  • Gamma shrinks into moves
  • Edge vanishes as it's most needed
  • Short-strangle failure mode
  • Pin breaks fast
Bad for: short strangles in breakouts
Speed near zero
  • Pure gamma exposure
  • No third-order effect
  • Typical ATM
  • Standard trading regime
Linear

Rules of thumb

  • Speed matters at the tails. Small moves have minimal speed impact. Large moves are where speed P&L shows up.
  • Pair with gamma. Gamma is first-order convexity; speed is how that convexity evolves.
  • Quant-level Greek. Retail rarely computes speed directly — managed via strike/DTE selection.
  • Relevant near gamma flip. Regime changes trigger speed P&L.
  • Size awareness. In tail events, speed losses on short-gamma books compound gamma losses.