system
A chat on subreddit /r/NoStupidQuestions
human
To extend this a bit. Jews were great traders and lenders because all across Europe, the Middle East, and elsewhere, they all spoke a common language, Hebrew. If you wanted some cotton from an Egyptian and you only spoke English, you’re Jew associate could speak with their jew associate and you could get your cotton. For a small transaction fee. But both sides hated this transaction fee and demonize the Jew for it. And  from the outside observer it looked as though the Jew was controlling the whole transaction, which later became controlling the whole world.
gpt
Also, for religious reasons they had a strong scholarship tradition and didn't keep their private languages restricted the way the church did with Latin.  In a medieval or early Renaissance world where the average person was illiterate, the average Jewish trader spoke two to four languages.  That provided connections and options.