So, my sister lives in Canada and she travelled to US and change some of her currencies to US currencies(about $100 US). A week later, she went back to Canada and tried to change her US currencies back to Canadian ones. The equivalence of US currencies went down and she lost about ($10 Canadian). I'm wondering if this happened to anyone and lost a lot of money? What did you do?
This happens. There is not much to do about it once the loss has occurred. It's just a risk that's inherent in exchanging money.
(Most of your sister's loss must have been in fees or buy/sell spread rather than exchange rate moves, because the USD/CAD rate has not moved as much as 10% during the last year).
You can try to minimize your exposure to exchange-rate losses by
not exchanging more money that you think you'll need to spend.
pay with a credit or debit card when abroad. The card issuer will exchange only the amount you actually spend.
if you're often going to the same country, consider keeping your stash of emergency cash from trip to trip instead of changing it back to your own currency when you get home.
bring emergency cash in your own currency and exchange it locally only if an emergency that you need to cover arises. Exchanging the money abroad may be more expensive than at home, but in most cases you won't need to (because no emergency).
This happens to everyone everywhere when exchanging currencies.
- The exchange rates between currencies varies everyday due to many factors. You can "gamble" by exchanging your money when you feel it is advantageous to you (when the rates are high).
- Banks (and exchange offices) will buy and sell currencies are different rates. For example, my Canadian bank will buy US dollars at 1,2744 and sell at 1,3451.