I'm not really a currency guy, but I think I'm still missing Jonathan's point, and I may let that continue. Too many paying clients waiting on my pearls of wisdom. Interest rates fluctuate frequently, Jonathan, without any government action. Inflation expectations, anticipated currency revaluations, creditworthiness of government or private borrowers, and etc. The arbs and their computers ensure that these changes are instantly reflected in the currency contracts.
I think one missing piece might be that Oswaldo views these forward contracts as symmetric. There is a mirror image on each side of the transaction. You always see them from your perspective in dollars buying euros, but someone else is selling euros to you and receiving dollars in exchange later. The various parties' supply and demand for future currency for every reason under the sun--wine, vacation homes, pure trading--are balanced in the price, and what's left is the carrying cost, almost entirely the difference in interest rates for dealers who are active in the market and trade in volume. The markup to a retail buyer is higher, but still not directional--it's about the same for the guy in Avignon who chooses to spend his summers in Washington. (OK, maybe that guy is nuts and you can charge him more).
I think one missing piece might be that Oswaldo views these forward contracts as symmetric. There is a mirror image on each side of the transaction. You always see them from your perspective in dollars buying euros, but someone else is selling euros to you and receiving dollars in exchange later. The various parties' supply and demand for future currency for every reason under the sun--wine, vacation homes, pure trading--are balanced in the price, and what's left is the carrying cost, almost entirely the difference in interest rates for dealers who are active in the market and trade in volume. The markup to a retail buyer is higher, but still not directional--it's about the same for the guy in Avignon who chooses to spend his summers in Washington. (OK, maybe that guy is nuts and you can charge him more).