Answer
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:
1- A Muslim is not allowed to help promote and market that which is unlawful. We recommend that you look for a new job.
2- It is permissible that you benefit from the salaries because what is unlawful relates to the work that you have been doing, and not the money itself.
Answering your question, the General Iftaa’ Department in Jordan, states the following:
If by Foreign Exchange Trading, you are referring to (Forex|) or (Margin Trading), then they are not permissible because they include violations of the Shari`ah.
In addition, a Muslim is not allowed to help promote and market that which is unlawful. Therefore, we recommend that you look for a new job.
As for the salaries that you have received, it is permissible that you benefit from them, because what is unlawful relates to the work that you have been doing, and not the money itself.
Almighty Allah knows best.
Source: www.aliftaa.jo