exchange

reciprocal transfer of equivalent sums of money especially the currencies of different countries; "he earns his living from the interchange of currency"
the act of giving something in return for something received; "deductible losses on sales or exchanges of property are allowable"
a workplace for buying and selling; open only to members
exchange or replace with another, usually of the same kind or category; "Could you convert my dollars into pounds?"; "He changed his name"; "convert centimeters into inches"; "convert holdings into shares"