Methodology
For every day, each coin spent is compared against the price it was last acquired at. If it moved at a gain, the difference counts as realised profit; if at a loss, as realised loss — both expressed in native BTC. Coins are grouped into vintage-year cohorts (the year they were created), so each coloured line shows the daily net realisation of one creation-year cohort, and Total is the sum across all cohorts.

Aggregation: the default view is the trailing 365-day sum — the regime view, where the shaded red bands mark periods of negative trailing-year net realisation and dashed vertical lines mark the zero crossings (late 2018 and 2022 — the two capitulation regimes). The 7d / 30d / 90d EMA modes show the smoothed daily flow instead (7d matches the reference chart). By default only Total and Price are shown; click any vintage year in the legend to add its cohort line.

Reading it: net-realisation tops cluster at cycle euphoria (old coins waking up into strength); sustained negative regimes mark capitulation, when coins are being spent at a loss and weak hands hand supply over to strong ones.