Is the interest resulting from a deposit in an investment bank permissible or forbidden, knowing that the bank invests these funds in commercial or real estate ventures?

It is permissible to invest money in Islamic banks that adhere to Sharia controls in Mudarabah (profit-sharing) contracts, such as not guaranteeing the capital or specifying a known profit amount, as this invalidates the contract and makes the profits usurious interest. It is not permissible to invest in non-Islamic banks that invest in forbidden things, because that is aiding in sin. A Muslim must be wary of doubtful matters concerning their wealth, for usury is stripped of blessing and is fought by Allah and His Messenger.