The SpotGamma implied 1-day move is displayed each day in the Founder’s Notes as our proprietary estimate of the expected 1 standard deviation range for the next day, which is the expected move based on historical data with 68.3% confidence.

It is also available right from the Dashboard on the key levels for SPX, SPY, QQQ, NQ, and RUT.

This is not a simple formula derived from implied volatility, but something that uses analysis based on decades of historical datasets.

In other words, this is a historical-based analysis of an expected move which complements calculations based on what the options market is providing.

You can determine the expected range for the day by adding or subtracting the value of the 1-day move from the current S&P reference price.