I was surprised to see that the term “bankster” was coined by Ecuadorians 6-7 years ago.  This term has been used by the fringe of the far right in the USA for at least 70 years in reference to some sort of conspiracy involving bankers and the Federal Reserve.

Example: “For the rest of your life you will be in a position of power over your money. You will have the rare advantage to turn the tables on politicians, banksters, and newspaper editors.”  see URL

Example: “How the Banksters avoid the Fractional Reserve Requirements.” see URL
The word also has some anti-Semitic references.

Example: “After three and a half years, Rome will break her agreement with the Jewish banksters who, together with the Black Nobility, will hate the whore and transfer their allegiance to Judaeo-Communist Russia - becoming Gog, the chief ruler of Magog who will ‘nuke’ Vatican City State and the United States of America, thereby precipitating Armageddon.” see: URL

Example: “Make sure that our Marxist paid political stooges in positions of leadership “borrow” enormously from our Jewish Banksters to put their Nations in outrageous debt to us.” see: URL