thinkscript Gamma Heatmap in Option Chain for Thinkorswim (FREE)

# === GAMMA HEATMAP COLUMN FOR OPTION CHAIN ===

# Author: 0DTE_SPX | https://0dtespx.gumroad.com | https://x.com/0DTE_SPX

#

# DESCRIPTION:

# This script visualizes per-strike gamma (NOT GEX) in the ThinkOrSwim Option Chain.

# The preview image shows the gamma heatmap in the far left column, paired with other heatmaps to help supercharge the SPX Option Chain. Explore other heatmaps in my link above.

# It colors each row with a smooth green gradient if gamma() is positive.

# Gamma by nature increases as it gets near the money and vice versa. It increases the most the closer it gets to expiration and price combined—end of the day.

# Strikes with low gamma appear light green; high gamma appears dark green.

# Gamma values < 0.02 are ignored (plotted as white) since it show lack of interest. This is a preference and you can adjust values anytime.

# Stay focused on strikes that are likely to be active. Works well on SPX 0DTE towards the last RTH hour.

# NOTICE: Only updates during regular trading hours.

# FEATURES:

# - Green shaded Heatmap to help visually spot active strikes.

# - Ignores or de-emphasizes strikes with gamma < 0.02 (less actionable).

# - Dynamically adjusts background and text color for visibility.

#

# BENEFITS:

# - Spot where market makers are most active or vulnerable to delta hedging pressure.

# - Works intraday — gamma shifts live with option activity and price movement.

#

# ⚠️ NOTE:

# - This script shows per-option gamma() — it is not total GEX.

# - For GEX (gamma × OI × 100), use the “GEX Chain Heatmap” script instead.