Suppose we have a portfolio with many assets.
Since this portfolio receives monthly contributions and withdrawals, what is the best method to evaluate its global rate of return and avoid computing these contributions as a "profit" and withdrawals as "losses"?
I've already seen some people using abstract entities (e.g.: we may define that we start with 100 entities, and, for a \$100 portfolio, each entity would cost \$1), but I don't know the name of this method in English.