Bitcoin's ledger is public, so analysts can study it in ways impossible for any other asset. The Bitcoin Charts dashboard carries the main metrics. Here is what they mean.
Supply by age (HODL waves)
How long since each coin last moved. A large share of supply untouched for over a year means holders are not selling; it rises through bear markets and falls near tops as old coins move to new buyers.
Realised price and MVRV
Realised price values every coin at the price it last moved, so it approximates the market's aggregate cost basis. MVRV is market value divided by realised value: how far price sits above or below what holders paid. Historically extreme highs have marked euphoria and dips below 1 have marked capitulation. "Historically" is doing a lot of work in that sentence.
Exchange flows
Coins moving onto exchanges are available to sell; coins leaving are going to custody. Sustained outflows have accompanied accumulation phases. The data is messy: exchanges move internal funds, and labelling addresses is guesswork.
Miner behaviour
Hash rate, miner revenue, and whether miners are selling or holding what they mine. The hash ribbons chart flags miner capitulation, when weak miners shut off and difficulty falls.
The rule
On-chain data describes what holders did. It does not tell you what they will do, and every metric that "called the top" was fit to past tops. Use it to understand the market's state, overlay it with price, and resist turning it into a trading signal.