An analysis of the tension between the halachic categories of sheves and mevatel kiso shel havero, and their application to various situations. The Yerushalmi (B.M. 5:3) writes that in a case of mevatel kiso shel chaveiro - a person restrained his friends money and prevented him from earning profit - the friend has only a complaint against him (Pischei Choshen, Nezikin 3:29). Many authorities consider mevatel kiso shel chaveiro a form of grama. As such, there remains a moral obligation. However, since there is no loss of capital, some maintain that there is not even a moral obligation, only a complaint (see Shach 61:10, 292:15; Responsa Imrei Binah #1).
If there is a definite loss of profit or regular earnings, some maintain that there is a legal liability of garmi. However, others maintain that preventing clear profit also remains grama (see Aruch Hashulchan 61:11; P.C., Nezikin 3:[72-73]).
Even one who withheld anothers money and earned profit from it does not have to share the profit with the owner. However, if the owner demanded the money back in order to invest it, but the recipient continued to withhold it, some maintain that he must share his profits from the money with the owner (Rema, C.M. 292:7).