In Medevial Europe Jews weren't allowed to own land and made money as merchants or banking. People didn't understand the role they played in the economy and blamed them whenever prices rose in famines and for all other types of ills.

Rulers often would whip up pogroms raiding the goods and money of the merchants to support themselves.

In our day it is intertwined with comunism where the role of capital, management, and arbitrage is hand waved as greed and exploitation.