How much is one “lot” of EUR/USD?
"A lot (sometimes called a round lot) always refers to the quantity of physical good that you're getting, like a carton of eggs or a barrel of oil.  The tricky thing in the case of forex is that the physical good also happens to be a currency. A spot currency product trades in the denomination on the right-hand side (RHS) of the product name.  So if you're buying EUR/USD you are paying USD currency to get EUR ""units"", and if you're selling EUR/USD you are receiving USD by giving away EUR ""units"".  The EUR is the ""physical good"" in this case. The way I remember it is to think of all products (not just currencies) as trading pairs.  So AAPL in my mind is AAPL/USD.  When I buy AAPL/USD I am paying USD to get AAPL units.  When I sell AAPL/USD I am receiving USD by giving away AAPL units. The thing on the left is the physical good (even if it happens to be money) that you are exchanging, and the thing on the right is the money that you are exchanging. So, when I buy a lot of AAPL, I am buying 100 shares at their current price in dollars. Similarly, when I buy a lot of EUR/USD, I am buying 100K Euros at their current price in dollars."
I don't believe from reading the responses above that Questrade is doing anything 'original' or 'different' much less 'bad'. In RRSPs you are not allowed to go into debt. So the costs of all trades must be covered.  If there is not enough USD to pay the bill then enough CAD is converted to do so.  What else would anyone expect? How margin accounts work depends on whether the broker sets up different accounts for different currencies. Some do, some don't.  The whole point of using 'margin' is to buy securities when you don't have the cash to cover the cost.  The result is a 'short' position in the cash.  Short positions accrue interest expense which is added to the balance once a month.  Every broker does this. If you buy a US stock in a USD account without the cash to cover it, you will end up with USD margin debt.  If you buy US stock in an account that co-mingles both USD and CAD assets and cash, then there will be options during the trade asking if you want to settle in USD or CAD.  If you settle in CAD then obviously the broker will convert the necessary CAD funds to pay for it.  If you settle in US funds, but there is no USD cash in the account, then again, you have created a short position in USD. I think you are asking a few questions here. Why is gold chosen as money? In a free market there are five characteristics of a good money: Gold and silver meet all five characteristics.  Diamonds are not easily divisible which is why they are not normally used as money.  Copper, Iron, and lead are not scarce enough - you would need a lot of these metals to make weekly or daily purchases.  Paper is also way too plentiful to be used as money. By the way, historically silver has been used for money more than gold. How does international trade work with gold as money (is this what you are asking with your hypothetical example of 10 countries each with y amount of gold?) Typically a government will issue a currency that is backed by gold.  This means you can redeem your currency for actual gold.  Then when an American spends 5 US dollars (USD) to purchase a Chinese good the Chinese man now owns 5 USDs.  The Chinese man can either redeem the 5 USD for gold or spend the 5 USD in the US.  If a government issues more currency then they have gold for then the gold will start to flow from that country to other countries as the citizens of the other countries redeem the over-issued currency for gold.  This outflow of gold restricts governments from over-issuing paper currency. Who creates the procedures and who supervises them in modern worldwide economy? The Federal Reserve, IMF, and Bank of International Settlements all are involved in the current system where the US dollar (see Bretton Woods agreement) is the reserve currency used by central banks throughout the world.  Some think this system is coming to an end.  I tend to agree. "The simplest answer would be: Because they can. Why charge less for something if people will pay more? One example are Apple products. While there the price number is not exactly the same in EUR and USD, they are so close that, effectively, the EUR product is more expensive. Many things go into a price. There might be reasons for products in the EU being more expensive to produce or distribute. Or people in the EU might be in general more willing to pay more for a certain product. In that case, a company would forgo profits when they offered it cheaper. Also, prices are relative. Is the USD price the ""correct"" one and the exchange rate should dictate what the EUR price is? Or vice versa?" You have currency risk either way.  The only question is deal with it now or later.  No one can tell you which action is better until we look at it in hindsight.  You could hedge and move some now, some later.  Invest your USD in US equities and move some to EUR and invest that in EUR companies. I'd suggest having your money in the same currency as where you are living, since for the most part, you'll be in the same boat as your peers and neighbors.  If you have high inflation, so will your friends and neighbors and you won't feel so bad.  And if your currency gets stronger, then so will the currency of the people you are hanging out with. It's similar to betting on Don't Pass in craps.  If you bet against the rest of the table, you could win when they lose, but then all your friends will be sad and you'll be happy. And vice versa, when your friends are high-fiving, you'll be in the dumps. I'd say it's better to be in the same boat as your peers since that's usually how we judge our happiness when we compare our situation to others. See the FX section of the quantitative finance SE data wiki. There are two basic ways you can separate your investments from the dollar (or any other currency). You will most likely not be able to avoid some form of format conversion, regardless of which data you use since there is, afaik, no standard for this data and everyone exports it differently. One viable option would be, like you said yourself, using the free data provided by Dukascopy. Please take into consideration that those are spot currency rates and will most likely not represent the rate at which physical and business-related exchange would have happened at this time. Here's what the GnuCash documentation, 10.5 Tracking Currency Investments (How-To) has to say about bookkeeping for currency exchanges. Essentially, treat all currency conversions in a similar way to investment transactions.  In addition to asset accounts to represent holdings in Currency A and Currency B, have an foreign exchange expenses account and a capital gains/losses account (for each currency, I would imagine).  Represent each foreign exchange purchase as a three-way split: source currency debit, foreign exchange fee debit, and  destination currency credit. Represent each foreign exchange sale as a five-way split: in addition to the receiving currency asset and the exchange fee expense, list the transaction profit in a capital gains account and have two splits against the asset account of the transaction being sold. My problems with this are: I don't know how the profit on a currency sale is calculated (since the amount need not be related to any counterpart currency purchase), and it seems asymmetrical.  I'd welcome an answer that clarifies what the GnuCash documentation is trying to say in section 10.5.