Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa. v13 p506 no.3134
Question: Advise us, may Allaah increase you in knowledge, about the ruling of having shares in the Saudi-American Bank. Is it ribaa, since it trades in interest and is based upon interest, as we know?
Response: The Saudi-American Bank and other banks, if they are based upon ribaa and trade in ribaa, then it is not permissible to have shares in them. This is because it is regarded as assisting in sin and transgression, and Allaah has prohibited this, as He سبحانه و تعالى says:
{but do not help one another in sin and transgression} al-Maa.idah 5:2
And with Allaah lies all success and may Allaah send prayers and salutations upon our Prophet ﷺ and his family and his companions.
