Is investing in bank funds for stock speculation permissible?

It is permissible to invest money in Islamic banks that adhere to Sharia principles and invest in permissible stocks, and it is lawful to benefit from the profits generated thereby. However, if the investment is in prohibited stocks, such as those of interest-based banks and commercial insurance companies, then it is not permissible. A Muslim must seek what is lawful in his earnings, as the Prophet (peace be upon him) said: "The feet of a servant will not move on the Day of Resurrection until he is asked about four things: about his youth and how he spent it, about his life and how he used it up, about his wealth - from where he acquired it and in what he spent it, and about his knowledge - what he did with it."