Explanation

An MRI of 100% means they have spent all the coins they have mined. A reading above 100% means they have spent more than they have mined, drawing down on their inventory. A reading below 100% means the miners are building up their inventory.

Inventory management is a key component of running an effective mining operation. Miners that run tight profit margins or have poor balance sheet management are forced to liquidate inventories quickly. Miners that have secured a relatively lower cost base can afford to build their balance sheet, assuming they are long on bitcoin. Consequently, MRI informs us of evolving miner sentiment.