Simplifying it , we can start with one major currency pair that in this example is the EUR/USD meaning that the euro is the base currency for the buy or sell order. If you think that the US economy would continue to weaken, which is bad for the US dollar, you should execute a BUY EUR/USD order. By doing this, you have bought euros with the expectation that they will rise against the US dollar.
If you believe that the U.S. economy is strong and the euro will weaken against the U.S. dollar you would execute a SELL EUR/USD order. By doing so you have sold euros in the expectation that they will fall versus the US dollar.
Another example of USD/JPY , where the U.S. dollar is the base currency and thus the “basis” for the buy/sell.
If you think that the Japanese government is going to weaken the yen in order to help its export industry, you would execute a BUY USD/JPY order. By doing so you have bought U.S dollars in the expectation that they will rise versus the Japanese yen.
If you believe that Japanese investors are pulling money out of U.S. financial markets and converting all their U.S. dollars back to yen, and this will hurt the U.S. dollar, you would execute a SELL USD/JPY order. By doing so you have sold U.S dollars in the expectation that they will depreciate against the Japanese yen
If you believe that the U.S. economy is strong and the euro will weaken against the U.S. dollar you would execute a SELL EUR/USD order. By doing so you have sold euros in the expectation that they will fall versus the US dollar.
Another example of USD/JPY , where the U.S. dollar is the base currency and thus the “basis” for the buy/sell.
If you think that the Japanese government is going to weaken the yen in order to help its export industry, you would execute a BUY USD/JPY order. By doing so you have bought U.S dollars in the expectation that they will rise versus the Japanese yen.
If you believe that Japanese investors are pulling money out of U.S. financial markets and converting all their U.S. dollars back to yen, and this will hurt the U.S. dollar, you would execute a SELL USD/JPY order. By doing so you have sold U.S dollars in the expectation that they will depreciate against the Japanese yen