My history teacher mentioned some things so I'll outline it here, but I'd like to see what you guys say.
It started from the Middle Ages. The majority of people were Catholics and largely uneducated. The Church wasn't educating anybody and would not allow the people to read. (Because the Bible has that heartless liberal named Jesus and we can't have that-end sarcasm) So the Jews started taking higher education jobs, such banking(and doctors etc) And everyone hates the idea of compound interest so they naturally think they are cheating them and are greedy.
So I don't have any sources, as it was just a lecture, but I'm wondering how accurate that thought was or if there's other origins.
The Church wasn't educating anybody and would not allow the people to read
Things like monastic schools, universities, etc would suggest that this is, in fact, quite inaccurate
So the Jews started taking higher education jobs, such banking
In most parts of Europe, Jews were restricted from most forms of employment, save usery, that is, lending money and charging interest. This was considered 'unchristian', hence it was one of few areas in which European Jews might be able to find employment.
The medieval historians should be able to expand on this, and you could also check the FAQs section on the wiki.
you may find this section of the FAQ useful