Money as a stock variable is measured at a specific point in time, representing a set quantity regardless of time periods.
Money as a stock variable means that the quantity of money is measured at a specific point in time, independent of time periods. For example, when we know the balance in a checking account is $1,000, it is a stock variable as it represents a specific amount at a given moment. Stock variables are contrasted with flow variables like income, which require a time dimension to be meaningful.