# Determining the basis for capital gain [duplicate]

If the value of the US dollar is greater than what I originally exchanged it for, is it considered capital gain? If so, how do I determine the amount I gained?

EDIT: For example, I traded \$100 USD for Mexican pesos. I spent some of that money (logically I now have less than \$100 USD). But for some reason, the value of the peso skyrocketed so when I go to trade my remaining pesos for USD, I get back \$1000.

• If you are in US, then your basis is USD. So can you elaborate the transaction? Did you buy some other currency and sold it later there by making a gain in Fx? – Dheer Jul 11 '17 at 3:27
• I will wait for someone from US to put an answer. Say of the \$100 worth Mexican pesos, you spent \$10 worth of Mexican pesos. So on the balance of \$90 you got a value of \$1000. There is a Fx Gain of \$910 on which capital gains tax would be due. Some one with knowledge of US capital gains can indicate when the taxes are due; on actual conversion back to \$1000 or notionally when the value appreciates. Generally for individuals it would be when the conversion happened. Only corporates / Fx dealers may use accruals and pay on notional gain/loss. – Dheer Jul 11 '17 at 3:35