Over the past 30 days, $BTC and $ETH have moved almost as one, with a price correlation of 0.945 between them. A reading of 1 would mean the two rose and fell together in perfect proportion; 0 would mean no link at all.

The figure is built from 30 daily samples across that 30 day window. It measures how closely the two coins track each other, not which way either one is heading.

For anyone holding both, a reading this close to 1 means the two positions have behaved almost like a single bet over the past month.