Antisemitism (prejudice against, hatred of, or discrimination against Jews as an ethnic, religious, or racial group) goes way back to the ancient world, predating modern banking, Zionism, Islam, Christianity, and many other things that have been listed in this thread as cause or reason.
Esther 3:8-9, 13
New International Version (NIV)8 Then Haman said to King Xerxes, “There is a certain people dispersed among the peoples in all the provinces of your kingdom who keep themselves separate. Their customs are different from those of all other people, and they do not obey the king’s laws; it is not in the king’s best interest to tolerate them.
9 If it pleases the king, let a decree be issued to destroy them.
13 Dispatches were sent by couriers to all the king’s provinces with the order to destroy, kill and annihilate all the Jews—young and old, women and children—on a single day, the thirteenth day of the twelfth month, the month of Adar, and to plunder their goods.
History of antisemitism"The first clear examples of anti-Jewish sentiment can be traced back to Alexandria in the 3rd century BCE."
https://en.wikipedia.org/wiki/History_of_antisemitism#Classical_period