In plain English
MVRV is market cap divided by realized cap. If every coin is valued at the last price it moved on-chain, that pile is realized cap. Divide today’s market cap by that, and you get a “how rich vs cost basis” multiple.
Near 1, the market is about break-even for the average coin. Below 1, the average coin is at a loss. High multiples mean large paper profits. It can stay high for a whole bull — a thermometer, not a timer.