cambist

from The Collaborative International Dictionary of English v.0.48

Cambist \Cam"bist\, n. [F. cambiste, It. cambista, fr. L.
   cambire to exchange. See {Change}.]
   A banker; a money changer or broker; one who deals in bills
   of exchange, or who is skilled in the science of exchange.
   [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

CAMBIST. A person skilled in exchange; one who deals or trades in promissory 
notes or bills of exchange.