Expected Move Cone

Forward-looking probability cone from ATM implied volatility, showing where price is likely to move.

The Expected Move overlay draws a forward-looking probability cone on OHLC charts based on at-the-money (ATM) implied volatility:

Inner band (±1σ) — ~68% probability range. Price is expected to stay within this zone most of the time.
Outer band (±2σ) — ~95% probability range. Moves beyond this are statistically rare.

The cone starts from the current price and expands over time — wider bands mean higher uncertainty further out.

How it works:

Uses a log-normal model: upper/lower = spot × exp(±n × IV × √t)
In TOTAL mode, uses ATM IV from the expiration closest to 30 DTE — a clean, meaningful IV from a real tradeable expiry
In single expiration mode, uses that expiration's ATM IV and DTE
The cone automatically recalculates when you switch expiration or exchange — always reflecting the current selection's option chain data

Toggle: Use the checkbox in the top-right corner of the OHLC chart to show/hide the cone. Your preference is saved between sessions.

Trading tips:

Price consistently near the ±1σ edge suggests strong trending — momentum may continue
Price hugging the center suggests low realized vs implied vol — potential for mean reversion or vol crush
A break beyond ±2σ is a rare, high-conviction signal — consider reducing exposure or hedging