It is called  profit. And there's also a capital which usually comes before the profit emerges. Some person's invest having plans to withdraw the profit within a stipulated time frame. This timing could be after each time the profit gets a to a certain amount or it could be when it's a set time so they have to withdraw these funds and leaving just the capital. I
t's just like a circle so the capital stays and grows again up again. This would grow until another time that the investor is ready or the set time is reached or or the time limit is reached for the investment.  The funds are usually pulled off mostly to use for other purpose.