Live BTC rainbow price chart: a logarithmic regression of Bitcoin's price against its age, split into nine colour bands from "fire sale" to "maximum bubble". Updated daily from BTC close prices.
Bands shift up over time — the same price sits in a lower band every year. Log scale.
log10(price) = 2.6617 · ln(days + 1) − 17.9184
The centre line is a logarithmic regression of Bitcoin's price on the number of days since 2009-01-09.
The nine bands are fixed multiples of that centre (0.396987×, 0.539586×, 0.740738×, 1×, 1.350002×, 1.854705×, 2.553729×, 3.428273×, 4.663461×), so the bands widen in dollar terms as the centre rises but stay the same distance apart on a log chart. The coefficients are the published "v2" rainbow parameters, so Coinfuty's bands match the widely circulated version of the chart to six decimals; only the daily price input is ours.
The rainbow is a valuation heuristic, not a forecast. Historically the 2013, 2017 and 2021 tops reached bands 8–9 ("Sell. Seriously, sell!" / "Maximum bubble") while the 2015, 2018 and 2022 bottoms touched bands 1–2. Because the regression extrapolates ever higher, price has spent most of the time since 2022 in the lowest bands — a known limitation: the model assumes early growth rates continue, which each cycle has weakened.
Bitcoin closed at $81,245 on Sep 4, 2026, which is band 1 of 9 ("Basically a fire sale"). The next band up starts at $106,493, +31.1% above the current price.
It has bracketed every major top and bottom since 2013, but it is a curve fit, not a model with predictive theory behind it. Treat the bands as a rough long-term valuation gauge and combine them with other cycle indicators.
The log regression keeps rising at its 2010–2013 pace, while Bitcoin's growth has slowed each cycle. The centre line is now far above price, so even strong rallies only reach the middle bands.
Coinfuty calculates the chart from its own daily BTC close series (from July 2010) using published regression coefficients. Nothing is scraped from other rainbow-chart sites.
Not yet. The regression coefficients are Bitcoin-specific; a per-coin fit is planned for coins with at least four years of price history.
Coinfuty computes every series on this page from daily BTC close prices and public constants — the Bitcoin halving schedule, block subsidy and published regression coefficients. Values refresh nightly (00:20 UTC) and the current day is patched hourly. These are historical, backward-looking indicators; nothing here is investment advice.