Qitzur Shulchan Arukh – 65:19
It is permited for one to lend his friend 100 dinar so that he could buy goods at the market, so that when they return home the borrower will give him 120 dinarim for it — ONLY IF the lender receives the goods, takes them to his home, and the responsibility for them during the journey is on the lender. It is considered as if he has a share in the profits of the goods, since he took on responsibility.
In this halakhah, the likely scenario being discussed is that of two merchants going to the market together. One lacks the money to make full use of the market. So, he borrows from the other. Like in the previous halakhah, by assuming the risk for damages, one is assuming ownership. Therefore in our case the lender is sharing in the profits of their goods, becoming partners in the other’s market business, not simply lending money to the borrower at interest.