62% of $BTC supply hasn't moved in under 4 years. That's 12.48M coins.

The other 38% (7.59M) has been sitting for 4+ years — classic diamond hands.

This split matters because younger coins = recent buyers still in distribution mode. Older coins = conviction or lost keys.

Watch the <4yr cohort. If they start moving during a rally, that's your exit liquidity signal. If they hold through chop, accumulation phase continues.

HODL data is a liquidity map. Use it.