The range is defined by the pivot itself and a second value derived from the prior session's high and low. A wide band suggests the market is in balance and likely to range; a narrow band suggests imbalance and a higher chance of a directional day.
Traders also watch how the band sits relative to the previous day's: a band entirely above yesterday's is read as bullish positioning, entirely below as bearish, and overlapping as unresolved.
The evidence for these readings is mostly anecdotal, and the same information is available more richly from market-profile or initial-balance. The central pivot range's advantage is that it is computed before the session starts, which makes it usable for planning.
Related: pivot-point, initial-balance, market-profile, balance-area, prior-day-high-low