You’re not going to see it used in such terms because of how economics defines trade. However you will see examples that make it clear currency is a commodity subject to supply and demand when you look into exchange rates. https://www.investopedia.com/ask/answers/041515/how-does-bal...
Trade networks allow for stable equilibriums with no individual country having equal trade with any other county. To simplify, A on net sends money to B, and B buys stuff from C with A’s currency, C then buys stuff from A in A’s currency returning that money to A. However, people want to operate in their native currency and there are a lot more than 3 countries in the real world so you end with intermediary currency exchanges changes going on. In theory supply and demand steps in to balance things, in practice cash flows rarely actually sum to 0.
Trade networks allow for stable equilibriums with no individual country having equal trade with any other county. To simplify, A on net sends money to B, and B buys stuff from C with A’s currency, C then buys stuff from A in A’s currency returning that money to A. However, people want to operate in their native currency and there are a lot more than 3 countries in the real world so you end with intermediary currency exchanges changes going on. In theory supply and demand steps in to balance things, in practice cash flows rarely actually sum to 0.