I have a question on the tax implications on my foreign currency savings and currency trades. I moved to the USA in 2014 on an 3-year visa and am tax resident for part of the year. Following my move I opened a US based brokerage account and transferred all my holdings (unchanged) from my foreign brokerage account. This was required as the foreign broker would not accept a "US Person". I also hold a normal foreign bank account with cash EUR, deposited as salary and interest before my move to the USA. My primary currency in my US Brokerage account is EUR.
Since I moved to the US I have made several EUR transfers from my bank account to my brokerage account. Subsequently I converted some of those EUR to USD and one other currency (GBP) and used purchased shares/ETFs in USD and GBP. I have not traded back to EUR and not sold any shares.
My question is - is either of the currency trades (EUR to USD or EUR to GBP) or share purchases liable to trigger an income tax due to currency gain/loss? For example, the trade to USD could be considered against the exchange rate at the time I moved to the USA? Or the beginning of 2014? Or when I was paid the original EUR? Normally I would say a gain is triggered only when converting back to EUR, but since taxes are calculated in USD I am not sure what would be the reference against which a gain/loss would be calculated.