Portfolio Return

See: Internal Rate of Return - IRR.

A given portfolio produces a return (hopefully that return is positive and high, numerically).

How do you calculate the return? Well, from start to end, remember the magic formula: New minus Old, all over Old. So if the portfolio was worth $100 million when you started, and 5 years later it was worth $180 million, then you'd calculate by taking $180 million (new) minus $100 million (old) which is $80 million, over Old...which (again) is $100 million. So the total return over 5 years is 80%.