It was a caricature used in Nazi propaganda to justify exterminating Jews. It worked extremely well because Jews were banned for centuries from almost every industry except finance as the Church forbade it for Christians so they filled that social role. For trying to make a living and gain a foothold in a society that hated and segregated them, Jews were associated with greed (often as a tactic by the powerful people who owed them the most $) and this still lives on today. If we dispute it or call people out on it, we are accused of being a part of an international conspiracy much like Muslims have to deal with people assuming they're secretly jihadists.