Currency conversion rates fluctuate constantly, as currencies are traded 24 hours a day, states Investopedia. As exchange rates are determined by the ever-changing foreign exchange market, they may vary from one second to another.
Exchange rates are determined by the amount of currency bought and sold in a given period on the market. Various other factors affect exchange rates, with interest rate adjustments playing an important part, according to Investopedia. The demand for a specific currency is influenced by international trade, speculation, mergers and acquisitions, tourism and more. For this reason, exchange rates are often unpredictable and may vary considerably from one day to another.