Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Trading online or by telephone is permissible on the condition that debit and credit are done immediately.
Responding to your question, Prof. Dr. Monzer Kahf, Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
Trading of commodities online is permissible. You can make the sale and purchase for spot payment or on credit. Buying or selling currencies online or by telephone with a bank is permissible if debit and credit are done immediately in your two currencies accounts with the bank. If not, it is not permissible because taking immediate delivery is a must in currencies.
Trading in currencies online with exchange platform like FOREX is not permissible because it is harmful on the macro and no real delivery is ever done although they make fake credit and debit.
Allah Almighty knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.