The metric shows the difference between the number of new non-zero Bitcoin addresses added and the number of addresses that fully sold their coins (0 balance now) in a given daily interval.

Peak positive values indicate massive influx of new market participants and thus a FOMO sign.

Peak negative values either show capitulation events when people lose hope in market recovery when the price is low.

Or alternatively when prices are high it may mean an aggressive profit taking (in fact entire exit from the market) by many and the price drop is likely to follow or underway already.