Is the interest resulting from paying 15 Dinars and taking 30 Dinars, to be repaid in installments, with an annual profit of 25% of the amount paid achieved through its operation in trade and investment, considered Haram or Halal, like stocks and trade?

It is not permissible to subscribe to this society because it is based on usurious loans. The society pays a loan to the subscriber, who repays it in installments in exchange for subscribing to it with a certain amount. Scholars have unanimously agreed that stipulating an increase in a loan constitutes usury. If the loan is not conditional, then subscription is permissible, provided that the society invests its funds in permissible activities, that the profit percentage is shared and not from the principal, and that the subscriber's capital is not guaranteed.