This indicator helps to see how frequently all miners transfer Bitcoin to all exchanges. Miners periodically send a certain amount of Bitcoin to the exchange from their mining wallets. If they send Bitcoin to exchanges more frequently, the price will likely be bearish as they are selling bitcoin on the exchange, not through the OTC market.
This indicator is the total transferred amount from mining wallets that have received Bitcoin block reward. Miners periodically send Bitcoin to other wallets, but if the price is unusually high, they will sell bitcoin to the over-the-counter (OTC) market or exchanges. Significant miner outflow is a bearish signal.
It is all miners' outflow divided by its one-year moving average. If miners withdraw an unusually large amount of Bitcoins compared to the past year, the MPI increases, and the Bitcoin price is likely to be bearish. If you draw lines when MPI is higher than 2.5, it often matches local and global highs. On the other hand, if the MPI is low, miners hold Bitcoin, meaning it's likely to be bullish. They were HODLers in 2018 and 2020 great sell-offs though.