Realized Capitalization
A network valuation that prices each unit at the value it last moved at, instead of pricing every unit at today's price.
On a UTXO chain, each unspent output is valued at the market price on the day it was created and the results are summed, which approximates the aggregate cost basis of the supply. Because only units that move get repriced, the series changes slowly and is far less sensitive to a single recent trade than market capitalization, which is the reason it was introduced. The caveats are specific: transfers between a person's own wallets reprice units without any economic transaction, lost or abandoned units remain in the total at their old valuation forever, and the construction is difficult on account-based chains that do not track individual outputs. It is a measurement convention, not an audited flow of funds.
In practice
Units that have not moved for many years continue to be counted at the price prevailing when they last moved, regardless of what has happened since.
The common misunderstanding
Realized capitalization is not the amount of money invested in a network; internal transfers reprice units even though no purchase took place.