Gamma Scalping

Gamma scalping is a strategy that buys options, hedges their delta with the underlying and then rehedges as the price moves. Because a long option position has positive gamma, each rehedge sells the underlying after rises and buys it after falls, locking in small gains. Those gains are set against the time decay of the options. Gamma scalping makes money when the underlying moves more than the options' implied volatility predicted.

How it works step by step#

1. Buy options, often an at the money straddle, which starts close to delta neutral. See Straddle.
2. Hedge any remaining delta with the underlying.
3. When the price rises, the position's delta becomes positive (gamma). Sell shares to bring delta back to zero.
4. When the price falls back, delta becomes negative. Buy shares to bring it back to zero.
5. Repeat. Each round trip sells high and buys low, capturing a scalp.
6. Pay theta every day the options are held.

The break even move#

Gamma profits grow with the square of the move, while theta is a fixed daily cost. The break even daily move is where they balance:

break even move ≈ √(2 × |theta| / gamma)

With position gamma of 100 deltas per dollar and theta of $90 a day, the break even move is √(180 / 100) ≈ $1.34 a day. In theory, this break even corresponds to the implied volatility you paid. If the stock moves more than this on average, gamma scalping is profitable; if less, it loses.

Implied vs realised volatility#

The core bet is that realised volatility will exceed the implied volatility you paid for the options.

See Historical and Realized Volatility and Implied Volatility (IV).

When gamma scalping works best#

• Implied volatility is cheap compared with expected movement.
• The underlying is choppy, moving back and forth rather than drifting quietly.
• Short dated options, which have high gamma, though they also have high theta.
• Low trading costs, because frequent rehedging is required.

Rehedging choices#

• Fixed price bands: rehedge every $1 or every 1% move.
• Time intervals: rehedge at set times.
• Delta thresholds: rehedge when position delta exceeds a limit.

Wider bands capture bigger swings but risk missing reversals; tighter bands trade more and cost more. See Delta Hedging.

Risks#

• Quiet markets that bleed theta day after day.
• Volatility crush: falling implied volatility lowers the options' value through vega, even if realised volatility is fine. See Vega.
• Transaction costs from frequent rehedging.
• Trending markets can still be profitable, since delta grows with the trend, but hedging decisions become harder.

Who uses it#

Options market makers and volatility traders gamma scalp as part of managing long option positions. Individual traders can do it with liquid ETFs and options, but costs and the discipline of mechanical rehedging are major hurdles.

Frequently asked questions#

What is gamma scalping?#

A strategy that buys options and repeatedly delta hedges, selling the underlying after rises and buying after falls, to profit from price swings.

When does gamma scalping make money?#

When the underlying's realised volatility exceeds the implied volatility paid for the options, so hedging gains outweigh time decay.

What is the main risk of gamma scalping?#

Quiet markets, where time decay costs more than the small rehedging gains, and falls in implied volatility.

Next, learn the opposite approach of collecting time decay in Theta Harvesting.