... Seriously? Wow. Ok. If your local currency is not the USD and you have USD cash accounts or USD based investments, then you can hedge your currency exposure in the markets should you not want to be exposed to currency rate risk. Could be done in a number of ways... most do so through a retail FX brokerage or through currency options when they feel they still want a little upside on their hedge.
The capital balance would fluctuate with a lot of trades and frequent buy or sell the amount of currency trade would generate p/l for the currency acc
the fluctuation would be in accordance with underlying usd fluctuation. minimisation of usd weakness is the aim... costs will be incurred. it's not an alpha position