Gamma-Weighted Dollar Flow Proxy For ThinkOrSwim

[Flyingbulldog]

Custom Column in the option Chain...

What it Describes​

This indicator provides a proxy for intraday gamma-weighted dollar flow occurring in the current option contract. It highlights where gamma-sensitive option trading activity is taking place today, which may reflect institutional activity and associated dealer hedging.

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What the Numbers Mean​

1. The Value ($ Millions)​

Positive Number (+ Green): Positive gamma-weighted dollar flow.
Higher positive values indicate increased call-side gamma-weighted trading activity during the current bar.

Potential Market Effect: May be associated with conditions where dealer hedging dampens volatility or contributes to price stabilization.​

Negative Number (- Red): Negative gamma-weighted dollar flow.
Higher negative values indicate increased put-side gamma-weighted trading activity during the current bar.

Potential Market Effect: May be associated with conditions where dealer hedging amplifies volatility or contributes to stronger directional moves.​

2. Call Flow vs. Put Flow Direction​

The script uses option delta to distinguish call and put activity:
Calls = Positive Values (+) Retail usually buys calls -->Market Makers sell calls --> Market Makers are long gamma relative to underlying upside.

Puts = Negative Values (-) Retail usually buys puts Market Makers -->sell puts -->Market Makers are short gamma relative to underlying downside.

How to Use It in Your Trading Workflow​

Scan across strikes in the Option Chain for a specific expiration to quickly spot areas of unusually large gamma-weighted option flow.

Pattern in Chain	What It May Indicate	How Traders Often Interpret It
Huge Positive Spike	Large Call volume occurring at a specific strike	Pinning/ Resistance: Price often gets ****ed toward this strike and consolidates
Huge Negative Spike	Heavy Put buying occuring at a specific strike	Huge Accelerated Volatility Zone: If price drops through this strike, market maker hedging force can push down faster.
Net Vol Flip Point	The strike where total intraday transitions from Net Positive to Net Negative	Potential Shifts: Above this level, the market tends to be calm/mean-reverting; below it, intraday swings could become wider and faster.

# Hint: Calculates Volume Gamma Exposure (Vol GEX) in Millions ($M)
# Suitable for ThinkOrSwim Custom Option Chain Columns

# 1. Option Gamma & Current Option Bar Volume
def optionGamma = OptionGamma();
def optVol = volume;

# 2. Get Underlying Stock Price using the built-in fundamental data helper
def spotPrice = close(GetUnderlyingSymbol());

# 3. Determine if Call (+1) or Put (-1) using Option Delta
# Calls have Positive Delta (> 0), Puts have Negative Delta (< 0)
def sign = if OptionDelta() >= 0 then 1 else -1;

# 4. Calculate Dollar Volume GEX
# Formula: Gamma * Volume * 100 * Underlying Price * Direction Sign
def volGEXRaw = optionGamma * optVol * 100 * spotPrice * sign;

# 5. Convert to Millions ($M)
plot VolGEX = volGEXRaw / 1000000;

# 6. Formatting
VolGEX.SetDefaultColor(Color.CYAN);
AssignBackgroundColor(if VolGEX > 0 then Color.DARK_GREEN else if VolGEX < 0 then Color.DARK_RED else Color.CURRENT);