Initial balance (IB)

Example

Say period A, the first 30 minutes of the session, trades from $120.00 to $121.40, and period B, the next 30, trades from $119.60 to $121.00. The initial balance runs from $119.60 to $121.40, a $1.80 range. If the rest of the day stays mostly inside that band, the session looks balanced; if price extends far beyond it in one direction, it starts to look like a trend day.

Hypothetical numbers, for illustration only.