Theta Decay
PROGreeks & Risk · HTTP Data · Pro Tier
Overview
Theta Decay visualizes the time-decay exposure landscape across all listed strikes. It renders aggregate theta — the rate at which options lose value per day — separately for calls and puts, with a net composite. The result shows you exactly where time decay is concentrated and where it transitions from net positive to net negative (the "theta flip zone").
Two computation modes are available: absolute theta (|θ| × OI × 100) which shows total decay magnitude regardless of direction, and raw theta (θ × OI × 100) which preserves the directional sign. Switch between them to see different aspects of time decay.
Key Features
- Theta Flip Zone detection: Identifies strikes where net theta exposure changes sign — where the market transitions from being a net theta seller to a net theta buyer. Uses the same flip-line rendering plugin as Gamma Flip Zone.
- Absolute vs. raw theta toggle: |θ| mode shows the total magnitude of decay regardless of direction. Raw mode preserves signs — negative theta = option holders losing value, positive = rare situations where theta works for the holder.
- 7 chart types: Bar, Line, Area, Scatter, Step, Bubble, and Heatmap. Each renders theta exposure differently — bar for per-strike comparison, area for cumulative shape.
- View Options dropdown: Show Net, Net Only, Theta Flip Zones toggle, and the |θ| absolute toggle — all accessible from a single dropdown.
- ATM range filter: Narrow to near-money strikes where theta decay concentrations are most actionable.
- Premium themes: Full theme library for chart customization.
- Guide Panel: Educational overlay on theta exposure concepts and time-decay trading strategies.
How to Read the Chart
| Element | Meaning |
|---|---|
| Positive call theta bars | Call-side time decay contribution at each strike. Taller bars = more daily premium decay from call positions. |
| Negative put theta bars | Put-side time decay contribution. Negative because puts lose value on the downside. |
| Net theta line | Composite of call + put theta. Where net is largest, the most premium decays daily — prime territory for theta sellers. |
| Theta Flip Zone | The strike where net theta crosses zero. Analogous to the gamma flip — marks a regime boundary in time-decay exposure. |
Use Cases
- Premium selling strike selection: Sell options at strikes with the highest net theta — where time decay works hardest in your favor. These are the mathematically optimal strikes for credit spreads and iron condors.
- Theta decay acceleration: Near-dated options show steeper theta curves. Compare the theta shape across expirations to identify the expiry with the sharpest decay for premium selling.
- Theta flip zone awareness: If you're holding options near a theta flip zone, your daily P&L from time decay can flip direction — important for position management and stop placement.
How to Launch
Open the Window Launcher — click + or press L.
Search for Theta Decay or browse Greeks & Risk.
Click to launch and enter a ticker.
Data loads via HTTP. Use the View Options dropdown to toggle between absolute and raw theta. Enable Theta Flip Zones to see the zero-crossing annotations.
Data Source & Tier
Theta values derived from the options grid via Ohey's HTTP Data Abstraction Layer. Theta Decay is on the Pro tier ($79/month). View pricing →
Related Windows
- ThetaForge — Advanced theta analytics building on the decay data
- Vega Concentration — Compare time decay with volatility sensitivity exposure
- EigenHedge — Factor-based risk decomposition integrating theta dimensions