Realized reaction. Our earnings-calendar source publishes report dates but not whether a company reports before the open or after the close. To avoid guessing, the realized reaction is defined as the move from the close of the last session before the report date to the close of the first session after it — a two-session window that contains the reaction under either timing. It is labeled "reaction move" and is slightly wider than a pure one-day move.

Implied move. Ahead of each report (from launch onward), the site records the straddle-implied expected move of the first expiration after the reaction window, plus IV30 before the event. After the event it records the first post-event IV30, so the change in implied volatility across reports accumulates as an observable series. Implied moves for reports before the site began recording are shown as "not recorded" — they are not reconstructed.

Historical averages shown next to upcoming reports are the average and median of the stock's own past |reaction moves| over the available sample (sample size always displayed).