Is trading on the stock market and in Forex, through an Islamic financial brokerage firm, without leverage, where buying and selling are for speculative purposes and profits are immediately transferred to a bank account, and in various assets such as currencies, oil, gold, and company stocks, permissible or impermissible?

It is understood from what has been mentioned that speculation on options, futures contracts, and indices is Islamically prohibited, because the subject of the contract is neither money, nor a benefit, nor a financial right that can be compensated for. As for buying and selling real currencies with the aim of profiting from the price difference, provided that constructive possession is realized (such as a bank entry or transferring the amount to your account with the brokerage firm), it is permissible. You have done well in avoiding margin because it is an usurious loan. Therefore, it must be ensured that the speculation is actually on currencies and not on options contracts or price expectations only.