This is a very common question and still confuses many Binance users, especially those who are not very familiar with the financial market.
Buying cryptocurrencies in dollars:
The financial asset used as a reference for the value of cryptocurrencies is the US dollar (USD). This means that, regardless of the pair used for trading, the market understands that the US dollar is the basis for the average pricing. Even when you trade, for example, in the BTC/BRL pair, the quote is based on the BTC/USD pair. In other words: when you trade cryptocurrencies in pair with USD, it means that you are working directly with the price reference on a global scale, without the need for currency conversions.
Buying cryptocurrencies in reais:
When you buy cryptocurrencies in reais, the situation becomes a little more complex. This is because, as previously mentioned, the global reference is the US dollar. This is due to the direct influence of the exchange rate. For example, imagine that 1 USD – 6.04 BRL, if the value of the dollar starts to fall, it will be possible to buy more cryptocurrencies with the same amount of reais; on the other hand, if the value of the dollar rises, it will be necessary to spend more reais to make the same purchase. This means that strong fluctuations in dollar prices directly affect the performance of the asset in reais.