In the book 'Economics' by Mankiw and Taylor the demand and supply curves on the foreign-currency exchange market are shown as follows:
The supply equals the Net Capital Outflow (NCO). I would have assumed that the exchange rate influences NCO in the same way it influences imports and exports, for example a higher exchange rate makes it more profitable to invest abroad than domestically, leading to an increased NCO. However, the supply isn't influenced at all by the exchange rate according to Mankiw and Taylor and that's what I don't understand.