Is it allowed to work in an investment bank? my field is IT helpdesk. I am in a steady job but looking to move and would like to know whether I should consider working in an investment bank (as they pay more). I will only consider this option if Muslims are allowed to work in such jobs.
For example, the job could be deploying all of the PC’s with a new operating system like Windows 7.
In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
As a principle, when analysing the Shari’ah compliancy of any job, one must examine the nature of the job itself. If the hours at work are spent in permissible activities, then the job will be permissible. If the work rendered is impermissible, the job will be impermissible.
A person who works in the IT department of an investment bank is usually in charge of complex computer models, trading platforms, and communications systems. He has no direct association with the activities and trading of the bank.
According to the principles of Imam Abu Hanīfah (rahimahullah), this does not amount to assisting in sin. The job itself is free of any sinful transaction and activity. The job does not have a direct link with the usurious transactions the bank may undertake.  Hence, working in the helpdesk of an investment bank is in itself permissible.
And Allah Ta’āla Knows Best
Mufti Faraz Ibn Adam al-Mahmudi,