Correlate returns rather than price levels
Each hourly return is the natural logarithm of the current close divided by the previous close. The analyzer calculates Pearson correlation between BTC and ETH returns for the same hourly intervals. Correlating raw price levels can answer a different question and does not measure the same short-period co-movement.
Only completed hourly candles are eligible. A return requires consecutive timestamps exactly one hour apart in both assets. Missing periods are not forward-filled, and returns spanning those gaps are excluded. At least 20 valid aligned return pairs are required before statistics are displayed.
Read volatility and coverage together
Annualized realized volatility is sample standard deviation of hourly log returns multiplied by the square root of 8,760 hours. Annualization scales a historical variability measure; it does not forecast next year's volatility or return. A small sample can produce unstable correlation and volatility estimates.
The normalized close charts begin at 100 for visual comparison. They do not imply equal dollar risk. The summary also identifies the latest candle end and missing-data coverage, so an old or incomplete dataset cannot quietly appear to be a current full-window analysis.
Analyze your own data locally
The optional CSV uses the exact header timestamp,btc,eth. Supply epoch-millisecond timestamps for UTC hourly candle starts, with positive BTC and ETH close prices. Duplicate timestamps are rejected. Files are read in the browser and are not sent to BTCMox or a provider.
Use the export button to save the resulting statistics, return table and methodology notes. The output preserves the sample's interpretation and limitations rather than exporting an unexplained correlation number.